Do you drink water that's been left sitting out overnight or even for another day? Have you noticed it tastes different?

Tap water that has been left to sit out slowly begins to acquire(獲得) off taste. Many people think that this is because of microorganisms. But that's not what makes old water taste not fresh. For that we can thank carbon dioxide. After about 12 hours, tap water starts to go flat as carbon dioxide in the air starts to mix with the water in the glass, lowering its pH and giving it an off taste. But it's most likely safe to drink.

However, back to those microorganisms. If you use a dirty glass day after day, there is more of a chance of bacteria making themselves known; a risk that increases if you share the glass with another mouth as well. But assuming(假設(shè)) you use a fresh glass every few days, you probably won't have a problem unless the glass has been touched by dirty fingers, and especially if those dirty fingers went unwashed after using the bathroom.

As for plastic water bottles that have been left out in the sun or in the car, step away from the bottle, warns Dr. Kellogg Schwab, director of the Johns Hopkins University Water Institute. "A chemical called bisphenol-A, or BPA, along with other things used to make plastic can leach(過(guò)濾) into your water if the bottle heats up or sits in the sun," he explains. BPA, as you probably know, has been linked to everything from heart disease to cancer. Schwab also adds that plastic used for commercial bottled water isn't meant to be washed or refilled, so use only one time and recycle. Or don't buy them at all; use refillable water bottles instead.

1.Tap water begin to acquire an off taste because of______ .

A. BPA B. carbon dioxide

C. the glass D. the microorganism

2.According to Paragragh 2 , tap water that's been left sitting out for 12 hours____.

A. is still safe to drink B. tastes better

C. contains few microorganisms D. is most likely undrinkable

3.What should we do with plastic water bottles that have been left out in the sun or in the car?

A. Throw them away.

B. Clean them and use them again.

C. Use them after they cool down.

D. Refill them with fresh water.

4.Which of the following is true about BPA

A. It is safe for people to use.

B. It is a kind of new material.

C. It can cause great harm to people.

D. It is the main material to make plastic.

練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目：高中英語(yǔ) 來(lái)源：河南省安陽(yáng)市2017屆高三第二次模擬考試英語(yǔ)試卷 題型：短文改錯(cuò)

假定英語(yǔ)課上老師要求同桌之間交換修改作文，請(qǐng)你修改你同桌寫(xiě)的以下作文。文中共有10處語(yǔ)言錯(cuò)誤，每句中最多有兩處。錯(cuò)誤涉及一個(gè)單詞的增加、刪除或修改。

增加：在缺詞處加一個(gè)漏字符號(hào)(∧)，并在其下面寫(xiě)出該加的詞。

刪除：把多余的詞用斜線(xiàn)(＼)劃掉。

修改：在錯(cuò)的詞下畫(huà)一橫線(xiàn)，并在該詞下面寫(xiě)出修改后的詞。

注意：1．每處錯(cuò)誤及其修改均僅限一詞；

2．只允許修改10處，多者(從第11處起)不計(jì)分。

One day on my way to school, I went to buy the pancake in a food store, leave my bag on the table while waiting. With the pancake ready, and I paid for it, took “my bag” on the table, and hurriedly headed to school.

Seating in the classroom, I was about to take my books out while suddenly I became frozen. It was not my bag! I took the bag for mistake! What surprised me most was there was a large sum of money in it. Calming me down, I turned to the teacher for help.

At that time, I come to understand the true meaning of being honestly.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：安徽省合肥市2017屆高三第二次教學(xué)質(zhì)量檢測(cè)英語(yǔ)試卷（有答案) 題型：完形填空

I retired from my family business four years ago. But I've never been _____ of a challenge. I've sailed around the world before. And I've decided to fly east from Western Australia in a _____.

For the last two years I have trained hard, spending 150 hours______ with my ground team. When the big day came, thousands of people gathered to______ the launch. It was a______ start, with a smooth and steady takeoff. I was______ but still had some doubts—I was flying into the ______ I couldn't guarantee I'd see my friends and family again.

The capsule where I stayed was designed to _____ if I landed in water, but I was not sure whether I could _____ the cruelty of the Ocean. _____, I kept watching the weather, communicating with my land team and _____ altitude to achieve the perfect speed and direction.

On my fifth day, I was terrified to notice I was losing oxygen.______, I managed to save my life by adjusting the pressure in the oxygen cylinder (氧氣筒) to stop the oxygen escaping.

I know it was vital to stay______ to control the flight, altitude and my oxygen flow, so I held a spoon between two fingers—If I______, it would fall and wake me up. I never questioned why I was doing this. It is such a unique _____ to see our beautiful planet from high above.

Seeing the coast of Australia again on my 11th day was a huge _____. I knew my journey was nearly over. It was to be a new world record. I could see my team______ below as I flew over.

This _____ really pushed me to my limits, but it hasn't______ me. Next year, I want to fly even higher to break another______ for the hot-air balloon flight

1.A. shy B. skeptical C. fond D. confident

2.A. plane B. helicopter C. wing suit D. hot-air balloon

3.A. debating B. preparing C. carving D. traveling

4.A. welcome B. inspect C. delay D. witness

5.A. perfect B. false C. poor D. fresh

6.A. amused B. puzzled C. excited D. frightened

7.A. future B. unknown C. shelter D. reality

8.A. digest B. recycle C. float D. fly

9.A. survive B. show C. evaluate D. comment

10.A. Finally B. However C. Therefore D. Besides

11.A. losing B. ignoring C. proving D. adjusting

12.A. Strangely B. Luckily C. Normally D. Conveniently

13.A. calm B. awake C. patient D. relaxed

14.A. looked around B. carried on C. dropped off D. turned up

15.A. experience B. excuse C. dream D. tradition

16.A. loss B. disaster C. burden D. relief

17.A. exercising B. celebrating C. escaping D. quarreling

18.A. challenge B. accident C. race D. failure

19.A. interested B. confused C. annoyed D. discouraged

20.A. promise B. balance C. record D. barrier

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：浙江省2016-2017學(xué)年高二3月階段性考試英語(yǔ)試卷 題型：完形填空

Last year, I was lucky enough to work at an office near my mother’s house._________, I stayed with her for a month. During that time, I _________ her out with the housework and contributed to the groceries.

After a week, I started to _________ the groceries were running out pretty quickly.___________, I began observing my mother’s daily routine for two weeks. To my _________, I found she would pack a paper bag full of canned goods and _________every morning at about nine. She took the food to the slums(貧民窟) and distributed it to street _________.

I asked around and _________ my mum was popular in the area. The kids looked up to her as if she were their own mother. Then it hit me ——why didn’t she want to tell me about what she’d been doing? Was she _________ that I would stop buying the groceries if I knew the truth?

When she got home, I told her about my discovery and __________ she could react, I gave her a big hug and told her she didn’t need to keep it a __________ from me. She told me that __________ of the children lived with an old lady in a makeshift home while others____________on the streets. For years, my mum had been helping out by __________ whatever food she could __________. I was so moved by how __________ she was. She used what was__________for her to help others in need. And I was so __________ of her.

I __________ to buy groceries for my mum. But now, I always add a(n)__________bag for her other children.

1.A. However B. Besides C. Therefore D. Otherwise

2.A. slowed B. helped C. sent D. pushed

3.A. ignore B. understand C. complain D. notice

4.A. Confused B. Embarrassed C. Moved D. Annoyed

5.A. delight B. relief C. surprise D. regret

6.A. work out B. head out C. clean up D. get up

7.A. children B. strangers C. passers-by D. artists

8.A. made sure B. let out C. pointed out D. found out

9.A. angry B. hopeless C. worried D. frightened

10.A. once B. before C. until D. after

11.A. secret B. surprise C. gift D. reminder

12.A. few B. all C. any D. some

13.A. lay B. ate C. slept D. played

14.A. giving B. collecting C. receiving D. selling

15.A. lend B. spare C. find D. bring

16.A. curious B. cautious C. fearless D. selfless

17.A. meant B. cooked C. borrowed D. produced

18.A. tired B. fond C. scared D. proud

19.A. refuse B. long C. continue D. agree

20.A. large B. extra C. beautiful D. empty

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：2016-2017學(xué)年重慶市高一3月月考英語(yǔ)試卷（解析版） 題型：完成句子

1.His brother was a____________ to Beijing University last year.

2.The Chinese team has won many gold m____________ up to now.

3.I think the problem is of great importance and d___________ considering.

4.Since the problem has a__________, we should take action at once.

5.The boy is very clever and he shows high i______________ in study.

6.Though it’s difficult, we should e__________ all the possibilities.

7.Do not judge a person by his a_____________ which may lead to wrong conclusions.

8.High science and t__________ leads to fast development of economy.

9.Last week we went on a journey to Tibet, where we had a____________(glory) time.

10.She ____________(簡(jiǎn)化)the instructions so that the children could understand them.

11.I have not _______________(計(jì)算)the result of the math problem.

12.The wide ____________(應(yīng)用)of computers in life will free man from the heavy work.

13.With the help of the ____________(信號(hào))sent by the survivors, the rescue workers found the trapped explorers.

14.The _______________(古老的)building has a long history and many people visit it every year.

15.Since we are short of money, I can’t afford to buy a new car to _____________(替換)my old one.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：2017屆青海省西寧市高三上學(xué)期期末同步練習(xí)考試英語(yǔ)試卷（解析版） 題型：完形填空

Sometimes people around you can change your life. The change may not be sudden or ____, but little habits can produce big ____ that make you think about what is important in your life. The person who changed my life is Julia Masi. She has ____ me so many things that I will carry with me ____ my life.

One thing I've learned from Julia is how to balance ____. Julia has shown me how to ____ ahead so that I can finish all my school work, enjoy sports and ____ have time for my friends. She has taught me that you can do anything if you are ____ and if you never give up. I've also learned that you can find anything fun or ____ if you connect it with something that you enjoy.

Last year I hated studying vocabulary, but I loved playing on my computer. Julia ____ the two and showed me a website called “freerice.com” where you can ____ a word game that gives you 5 grains of rice to donate to the poor with every correct word. She ____ me to learn a hundred new ____ by filling up the rice bowl. I liked playing the game so much that I ____ about 1,000 words in just one month.

Julia has always ____ me to try new hobbies. She showed me that going to the theater could help me become a better writer. ____, she taught me that discussing a play can excite an interest in reading.

___ it wasn't for Julia I probably wouldn't have ____ how easy it is to help the poor. There are so many ways that one person can ____. I've learned to be more appreciative of what I own. I am ____ for the opportunities that I have been given. I will continue to think of ways to help those less fortunate for the rest of my life.

1.A. simple B. impressive C. necessary D. slight

2.A. results B. problems C. ideas D. decisions

3.A. taught B. served C. offered             D. bought

4.A. for B. of C. throughout D. into

5.A. work B. money C. career D. time

6.A. plan B. get C. move D. stay

7.A. never B. seldom C. yet D. still

8.A. excited B. determined C. careful D. patient

9.A. important B. easy C. possible D. interesting

10.A. shared B. remembered C. combined D. separated

11.A. watch B. play C. raise D. improve

12.A. challenged B. invited C. permitted D. reminded

13.A. lessons B. skills C. words D. stories

14.A. learned B. read C. used D. spelled

15.A. allowed B. warned C. forced D. encouraged

16.A. Therefore B. Besides C. However D. Otherwise

17.A. Unless B. Since C. Although D. If

18.A. realized B. noticed C. imagined D. dreamed

19.A. turn away B. make a difference C. show off D. make a mistake

20.A. ready B. sorry C. thankful D. anxious

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：河南省南陽(yáng)市六校2016-2017學(xué)年高二下學(xué)期第一次聯(lián)考英語(yǔ)試卷（有答案） 題型：書(shū)面表達(dá)

假如你是李華，今天被診斷出得了一種重病，需要住院治療相當(dāng)長(zhǎng)一段時(shí)間。請(qǐng)你對(duì)比生病前后你對(duì)學(xué)校學(xué)習(xí)生活的感受，寫(xiě)一篇文章。

注意：1.詞數(shù)100左右。

2.可適當(dāng)增加細(xì)節(jié)，使文章層次分明，行文連貫，

參考詞匯：被診斷有……病be diagnosed with

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：2016-2017學(xué)年河南省南陽(yáng)市六校高一下學(xué)期第一次聯(lián)考英語(yǔ)試卷（解析版） 題型：閱讀理解

Bali(巴厘島） is an Indonesia island that is rich in indigenous （本土的） culture．A lot of people say that Balinese culture is unique and that the people of Bali have always been contented with the “now”．If you ask a Balinese person what heaven is like, the probable answer will be "just like Bali"．This only goes to show that most Balinese people are happy to be where they are and never worry．

One factor that contributes to this laid-back lifestyle is the culture of close family ties in Bali．In the Balinese culture, support is always available．Balinese extended families are so tightly knit that all members usually reside in the same complex．

Hinduism(印度教）is one of the main religions in Bali.The Balinese culture is based on a form of this religion, which is called “Hindu Dharma”．This religion reached the island during the eleventh century．Most of the family customs and traditions as well as community lifestyles of the Balinese people are influenced by this．The religious influence even expands widely into the arts, which makes Bali distinct(不同于） from the rest of Indonesia．

In spite of the fact that tourists flood to the island every year, the Balinese people have managed to conserve their culture．Almost every native of Bali is an artist in some form or another．Parents and villagers have passed on their skills to their children, who all seem to have inclinations （意愿） either to music, dance, painting, and decor．

Another remarkable mark of the Balinese culture is the series of ceremonies and rituals（儀式） known as the Manusa Yadnya．This marks the different stages of Balinese life．Cremation （火葬） is very popular on this island，and unlike in the West, death is a joyous and colorful event for the Balinese．

1.What do we know about the Balinese according to the first two paragraphs?

A. They lead a very relaxing but unhealthy life．

B. They live in large families and are close to each other．

C. Their family members are distributed in different places．

D. Their extended families live too close together to get along well．

2.The underlined word “conserve” in Para．4 can be best replaced by “____”．

A. preserve B. spread C. Form D. expand

3.What is the text mainly about?

A. The Balinese religion． B. The lifestyle of Balinese．

C. Balinese culture． D. The tourism in Bali.

查看答案和解析>>

科目：高中英語(yǔ) 來(lái)源：山東省濟(jì)寧市2017屆高三第一次模擬（3月）英語(yǔ)試卷 題型：七選五

根據(jù)短文內(nèi)容，從短文后的選項(xiàng)中選出能填入空白處的最佳選項(xiàng)。選項(xiàng)中有兩項(xiàng)為多余選項(xiàng)。

Palm oil(棕櫚油) is the most widely used vegetable oil worldwide．It’s found in a wide variety of products from of vitamins to chocolate and bread．1. The former makes it easy to spread，while the latter makes it good for our body．

But the oil’s popularity comes at a high price．2. As a result，thousands of acres of rainforests in Indonesia，the world’s biggest palm oil producers，are being destroyed to make room for them．

With half of the world’s palm oil coming from Indonesia，orangutans(猩猩) have suffered a lot．3. What’s worse，in 2015，wildfires endangered one-third of the remaining orangutans．Palm oil farms have also threatened tigers and elephants and caused water and air pollution．

4. However，it’s not easy given that no other natural vegetable oil has both of its qualities．Now，scientists are creating a new oil to replace it by using food waste and M．pulcherrima，a yeast(酵母) that grows on leaves，fruits and flowers．5. Besides, the yeast can be widely produced in any weather．The scientists say their biggest challenge was to find a cheap way to change the sugars in the food waste to a form that the yeast can take in easily．The team is now trying to test if they can produce the oil at a lower cost．

A．Palm trees need lots of land to grow．

B．The easiest solution is to stop using palm oil so widely．

C．The palm oil is so expensive that many families can’t afford it．

D．In the last 20 years，over 80% of their habitat has been destroyed．

E．There are many things we can do to protect the endangered wild animals．

F．The oil is popular because it has a high melting point and contains healthy fats．

G．It eats the sugars from the waste and turns it into thick oil that has similar qualities to palm oil．

查看答案和解析>>

同步練習(xí)冊(cè)答案