，when Marx was already ，he began to learn Russian.

A.In 1870s； in his fifties

B.In 1870s； in fifties

C.In the 1870s； in his fifties

D.In the 1870s； in fifties

練習冊系列答案
相關(guān)習題

科目：初中英語 來源：2020年遼寧省營口市中考二模英語試卷 題型：單選題

___ you ____ my watch? Yes, I ____ it on the table just now.

A. Did , see , saw B. Did , see , see C. Have , seen, saw. D. Have , seen, have seen

查看答案和解析>>

科目：初中英語 來源：2020年山東省濟南市天橋區(qū)學業(yè)水平模擬英語試卷 題型：單選題

—The high-speed train ________ Jinan and Qingdao travels faster now.

—That's true. It only takes one and a half hours.

A.from B.among C.in D.between

查看答案和解析>>

科目：初中英語 來源：2020年江蘇省泰州市教育集團（聯(lián)盟）中考二模英語試卷 題型：回答問題

閱讀下面的短文，根據(jù)短文內(nèi)容回答問題。

The idea that red means stop and green means go has influenced our lives in more ways than just traffic signals (信號). We have been taught from a young age that the color red means danger and green means it’s okay to move forward. But why were those colors chosen for traffic lights in the first place? For something we have to look at every day, why couldn’t they have been prettier colors?

Well, it’s important to know that before traffic lights for cars, there were traffic signals for trains. At first, railway companies used red to mean stop, white to mean go, and green to mean warn. As you could imagine, trains ran into a few problems with white meaning go. For example, one train mistook a bright star for a white light and something unexpected happened. Because of that, railway companies finally moved green meaning go and used yellow to mean warn. And it’s been that way ever since.

Red has always been a color that mean danger, long before cars were even around. This most likely started because it’s the color with the longest wavelength (波長) so it can be seen somewhere farther than other colors.

But, believe it or not, yellow was once used to mean stop. Back in the 1900s, some stop signs were yellow because it was too hard to see a red sign in a poorly lit area. Finally, highly reflective materials (高反射材料) were developed and red stop signs were born. Since yellow can be seen well at all times of the day, school zones, some traffic signs, and school buses continue to be printed yellow.

So next time you are impatiently waiting at a traffic light, don’t get so mad at them, they’ve certainly come a long way.

Answer the following question with no more than 8 words.

1.How many colours have been used for traffic signals since the very beginning?

2.What did one train mistake for a white light?

3.Did the colour yellow mean go at first?

4.Why does red mean danger?

5.When were stop signs yellow?

查看答案和解析>>

科目：初中英語 來源：2020年江蘇省泰州市教育集團（聯(lián)盟）中考二模英語試卷 題型：單選題

—Thanks a lot for sending us so many masks and alcohol wet wipes (酒精濕巾). —________.

A.With pleasure B.That’s right C.All right D.Don’t mention it

查看答案和解析>>

科目：初中英語 來源：2020年江蘇省泰州市教育集團（聯(lián)盟）中考二模英語試卷 題型：單選題

—Can children under the age of 12 ride bicycles in your city? —No, according to the law, they ________.

A.shouldn’t B.mustn’t C.needn’t D.may not

查看答案和解析>>

科目：初中英語 來源：2020年重慶市區(qū)九年級學業(yè)調(diào)研抽測（二模）英語試卷 題型：改寫句子

The Chinese doctors are really great.（改為感嘆句）

__________ __________ the Chinese doctors are!

查看答案和解析>>

科目：初中英語 來源：2020年重慶市區(qū)九年級學業(yè)調(diào)研抽測（二模）英語試卷 題型：單選題

The mountain is __________ high __________ few people can reach the top.

A.so, that B.so, as C.as, as D.too, to

查看答案和解析>>

科目：初中英語 來源：貴州省銅仁市2020年中考英語試卷 題型：聽短對話回答問題

A.3. B.4. C.5.

查看答案和解析>>

同步練習冊答案