【題目】下列關(guān)于“驗(yàn)證機(jī)械能守恒定律”實(shí)驗(yàn)的實(shí)驗(yàn)誤差的說(shuō)法，正確的是（ ）

A．重物質(zhì)量的稱(chēng)量不準(zhǔn)會(huì)造成較大誤差

B．重物質(zhì)量選用得大些，有利于減小誤差

C．重物質(zhì)量選用得較小些，有利于減小誤差

D．打點(diǎn)計(jì)時(shí)器選用電磁打點(diǎn)計(jì)時(shí)器比電火花計(jì)時(shí)器誤差要小

【答案】B

【解析】為減小實(shí)驗(yàn)誤差，重物應(yīng)選質(zhì)量大些的，且重物質(zhì)量不需稱(chēng)量，A、C錯(cuò)，B正確；電磁打點(diǎn)計(jì)時(shí)器的振針與紙帶間有摩擦，電火花計(jì)時(shí)器對(duì)紙帶的阻力較小，故選用電磁打點(diǎn)計(jì)時(shí)器誤差大些，D錯(cuò)誤．

練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目：高中地理 來(lái)源： 題型：

【題目】關(guān)于能量轉(zhuǎn)化的說(shuō)法中正確的是（ ）

A．舉重運(yùn)動(dòng)員把重物舉起來(lái)，體內(nèi)的一部分化學(xué)能轉(zhuǎn)化為重力勢(shì)能

B．電流通過(guò)電阻絲使電能轉(zhuǎn)化為內(nèi)能

C．內(nèi)燃機(jī)的做功沖程是內(nèi)能轉(zhuǎn)化為動(dòng)能

D．煤炭燃燒的過(guò)程中能量不守恒

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】讀太陽(yáng)光照?qǐng)D（陰影部分代表夜半球）和太陽(yáng)直射點(diǎn)的回歸運(yùn)動(dòng)示意圖，據(jù)圖回答下列問(wèn)題。

（1）ME為晨昏線中的_____線。

（2）當(dāng)太陽(yáng)直射點(diǎn)由圖乙中③處移向④處時(shí)，地球公轉(zhuǎn)的速度變化情況為________。

（3）圖甲中早晨6點(diǎn)的是_____點(diǎn)。（填字母）

（4）A點(diǎn)的晝長(zhǎng)是_____小時(shí)，日落時(shí)間是_____點(diǎn)。

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】(2015·江蘇) The university started some new language programs to _____ the country’s Silk Road Economic Belt.

A. apply to B. cater for C. appeal to D. hunt for

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】【2015·陜西】C

The production of coffee beans is a huge, profitable business, but, unfortunately, full-sun production is taking over the industry and bringing about a lot of damage. The change in how coffee is grown from shade-grown production to full-sun production endangers the very existence of, certain animals and birds, and even disturbs the world’s ecological balance.

On a local level, the damage of the forest required by full-sun fields affects the area’s birds and animals. The shade of the forest trees provides a home for birds and other special(物種) that depend on the trees’ flowers and fruits. Full-sun coffee growers destroy this forest home. As a result, many special are quickly dying out.

On a more global level, the destruction of the rainforest for full-sun coffee fields also threatens(威脅)human life. Medical research often makes use of the forests' plant and animal life, and the destruction of such species could prevent researchers from finding cures for certain diseases. In addition, new coffee-growing techniques are poisoning the water locally, and eventually the world's groundwater.

Both locally and globally, the continued spread of full-sun coffee plantations (種植園)could mean the destruction of the rainforest ecology. The loss of shade trees is already causing a slight change in the world's climate, and studies show that loss of oxygen-giving trees also leads to air pollution and global warming. Moreover, the new growing techniques are contributing to acidic(酸性的) soil conditions.

It is obvious that the way much coffee is grown affects many aspects many aspects of life, from the local environment to the global ecology. But consumers do have a choice. They can purchase shade-grown coffee whenever possible, although at a higher cost. The future health of the planet and mankind is surely worth more than an inexpensive cup of coffee.

【1】What can we learn about full-sun coffee production from Paragraph 4?

A. It limits the spread of new growing techniques.

B. It leads to air pollution and global warming.

C. It slows down the loss of shade trees.

D. It improves local soil conditions.

【2】The purpose of the text is to .

A. entertain B. advertise C. instruct D. persuade

【3】Where does this text probably come from ?

A. An agricultural magazine.

B. A medical journal.

C. An engineering textbook.

D. A tourist guide.

【4】Which of the following shows the structure of the whole text?

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】下圖為我國(guó)某中學(xué)地理興趣小組利用所在城市人口資料繪制的人口金字塔圖。讀圖 回答下列問(wèn)題。

【1】2010年，該市0～4歲女性人口占總?cè)丝诘谋戎丶s為( )

A．3% B．6% C．6.2% D．4.2%

【2】該城市近三十年來(lái)人口結(jié)構(gòu)變化產(chǎn)生的影響是( )

A．青壯年養(yǎng)育子女的負(fù)擔(dān)逐漸加重

B．生育率逐漸增加

C．該城市逐漸邁向老齡化社會(huì)

D．青壯年男子逐漸外移

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】讀圖,完成下面小題。

【1】關(guān)于圖中景區(qū)的敘述,正確的是(　　)

A. 瀑布水量充沛,冬、春季節(jié)觀賞效果最佳

B. 瀑布規(guī)模較大,其形成以風(fēng)力侵蝕為主

C. 景區(qū)植被豐富,以落葉闊葉林為主

D. 景區(qū)地形復(fù)雜,易發(fā)生滑坡等地質(zhì)災(zāi)害

【2】黃果樹(shù)瀑布與十丈硐瀑布相比,景點(diǎn)規(guī)模相當(dāng),但旅游接待規(guī)模遠(yuǎn)大于十丈硐瀑布,其原因是黃果樹(shù)瀑布景區(qū)(　　)

①景點(diǎn)知名度高,游覽價(jià)值高　②緊鄰貴昆鐵路,交通通達(dá)性好　③地處熱帶,美學(xué)價(jià)值突出　④鄰近省級(jí)行政中心貴陽(yáng),環(huán)境承載力大

A. ①③ B. ②④

C. ①② D. ③④

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】污染系數(shù)(污染系數(shù)＝風(fēng)向頻率/平均風(fēng)速)可以用來(lái)反映風(fēng)對(duì)大氣污染的影響。下面是我國(guó)M市多年污染系數(shù)和多年風(fēng)向頻率統(tǒng)計(jì)圖。據(jù)圖回答下列問(wèn)題。

【1】據(jù)圖判斷，關(guān)于該城市污染系數(shù)的描述，正確的是(　　)

A．污染系數(shù)從正東向南北兩個(gè)方向遞減

B．風(fēng)速越大該市的污染系數(shù)越大

C．污染系數(shù)越大的方向污染越嚴(yán)重

D．污染系數(shù)西南偏西方向最小

【2】該城市應(yīng)采取的可行措施是(　)

A．將污染大氣的企業(yè)遷至城市北部

B．關(guān)閉所有污染大氣的企業(yè)

C．將污染大氣的企業(yè)遷至城市西部

D．污染物改為夜間排放

查看答案和解析>>

科目：高中地理 來(lái)源： 題型：

【題目】Your skin can ________ your body losing too much water.

A．keep B．prevent C．protect D．be stopped

查看答案和解析>>

同步練習(xí)冊(cè)答案