Billy is so tired _____ he worked all night in his office.

A. when B. because C. if D. so

練習冊系列答案
相關(guān)習題

科目：初中英語 來源：2016屆江蘇揚州市九年級上學(xué)期12月月考英語試卷（解析版） 題型：閱讀理解

Is there intelligent (有智力的) life on other planets? For years, scientists said “no.” or “we don’t know.” But today this is changing. Seth Shostak and Alexandra Barnett are astronomers(天文學(xué)家). They believe intelligent life exists (存在) somewhere in the universe. They also think we sill soon contact these beings(人；生物).

Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. “This is long enough for other planets to have intelligent life,” say Shostak and Barnett. The second reason is size—the universe is huge. “Tools like the Hubble Telescope(哈勃望遠鏡) have shown that there are at least 100 billion galaxies,” says Shostak. “And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth.”

In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes(高倍望遠鏡) allow scientists to discover smaller planets—the size of Mars or Earth—in other solar systems. These planets might have intelligent life.

Have beings from space already visited Earth? “Probably not,” says Shostak. “It’s a long way away. However, intelligent beings may contact us in other way, such as radio signals(信號). In fact, they may be trying to communicate with us now, but we don’t have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other.”

1.Seth Shostak and Alexandra Barnett are _____.

A. astronomers B. farmers

C. singers D. drivers

2.What is the best title for Paragraph 2?

A. The Age and Size of Earth

B. Our Galaxy: The Milky Way

C. Why Intelligent Life Might Exist

D. Earth: The Only Planet with Intelligent Life

3.Why was it hard to look for signs of intelligent life in the universe in the past?

A. There were not any smaller planets.

B. There were not any powerful telescopes.

C. The astronomers were not interested in them.

D. The Milky Way didn’t exist at that time,

4.Why haven’t beings from space visited us yet according to Shostak?

A. They’re afraid of us.

B. It’s a long way away.

C. They don’t want to see us.

D. They don’t know how to use radio signals.

查看答案和解析>>

科目：初中英語 來源：2015-2016學(xué)年浙江諸暨店口鎮(zhèn)第二初級中學(xué)八年級上期中英語試卷（解析版） 題型：選詞填空

書面表達

假設(shè)你叫李俊，你的美國朋友David想要在中國結(jié)交更多的朋友。你通過電子郵件，把你的同學(xué)王明介紹給他。王明情況見下表：

性 別

男

年 齡

14

外 貌

短發(fā)，高個子；

個 性

誠實，幽默

愛 好

癡迷于DIY

理 想

當一名校長 (headmaster)

要求：1. 注意文章條理，語句通順；

2. 詞數(shù)80左右，郵件的開頭和結(jié)尾已給出，不計入總詞數(shù)。

Dear David,

How are you? I’m writing to introduce my classmate Wang Ming to you.

___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

I hope you can make friends with him as soon as possible. Maybe you can show him around your country at the Spring Festival.

Best wishes,

Yours,

Li Jun

查看答案和解析>>

科目：初中英語 來源：2015-2016學(xué)年山東廣饒樂安中學(xué)五四學(xué)制六年級上學(xué)期期中英語試卷（解析版） 題型：單項填空

—How ______ you spell it?______.

A. do, K-E-Y B. are, K-E-Y

C. do, k-e-y D. are, k-e-yZ

查看答案和解析>>

科目：初中英語 來源：2015-2016學(xué)年江蘇揚州市七年級上學(xué)期期中英語試卷（解析版） 題型：單項填空

---Does she have a sister? ---- .

A. Yes, she doesn’t B. No, she does

C. Yes, she is D. Yes, she does

查看答案和解析>>

科目：初中英語 來源：2016屆四川遂寧市九年級上學(xué)期半期英語試卷（解析版） 題型：單項填空

Many trees ________ two years ago.

A. plant B.planted

C. were planted D.are planted

查看答案和解析>>

科目：初中英語 來源：2016屆山東慶云縣第五中學(xué)九年級上學(xué)期期中英語試卷（解析版） 題型：單項填空

Boys and girls, please read the sentences carefully. you are, mistakes you’ll make.

A.The more carefully, the fewer

B.The more careful, the less

C.The more careful, the fewer

查看答案和解析>>

科目：初中英語 來源：2016屆甘肅定西市九年級12月月考英語試卷（解析版） 題型：單項填空

The boy read the website and looked for some good suggestions for vacation spots.

A. careful enough B. enough carefully

C. enough careful D. carefully enough

查看答案和解析>>

科目：初中英語 來源：2015-2016學(xué)年江蘇建湖實驗初級中學(xué)八年級上學(xué)期期中英語試卷（解析版） 題型：單項填空

—Where is your father , Helen ?

—He is trying to _____a new shower in he bathroom.

A. put out B. put in C. put up D. put on

查看答案和解析>>

同步練習冊答案