Doyou know when and where to look for rainbows? We hardly ever see them because -组卷网

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Do you know when and where to look for rainbows? We hardly ever see them because they need two things together—sunlight (sunshine) and rain. We often can’t tell the color of sunlight with our eyes, but it has all the colors of a rainbow.

A rainbow appears (出现) when raindrops take these colors apart (分离). All these colors move fast at the same speed in the air: 671 million miles an hour. But when sunlight passes through water, it slows down. Some colors go through water faster than others. Red light goes first through water. Orange is almost as fast. Then comes yellow, green and blue. Purple light goes the last. As light meets water, it refracts (折射) and different speed makes different refraction. We can see a rainbow because sunlight makes some changes between the air and water.

A rainbow appears across from the sun. And when you see a rainbow, you can forecast (预测) the weather. If a rainbow appears in the morning, then the sun is in the east or southeast. So the rainbow is in the west or northwest. And weather usually moves from west to east. So maybe the rain is coming in your way. Things are different if you see a rainbow in the afternoon.

根据短文内容选择最佳答案。
【小题1】When can we see a rainbow?

A．On sunny and rainy days.

B．On cloudy days.

C．On snowy days.

【小题2】What does the underlined word “speed” mean in Paragraph 2?

A．光速

B．速度

C．空间

【小题3】What’s the main idea of Paragraph 2?

A．When to look for a rainbow.

B．Where to look for a rainbow.

C．What makes a rainbow.

【小题4】We can learn from the passage EXCEPT (除了) _________.

A．a rainbow appears across from the sun

B．you can see red, orange, yellow, green, blue and purple in a rainbow

C．you can look for a second rainbow outside the first one

【小题5】According to Paragraph 3, we can inter (推断) that ________.

A．the sun and the weather move in the same way

B．the weather will be good if you see a rainbow in the afternoon

C．you can see a rainbow if you look at the sun

22-23七年级下·黑龙江哈尔滨·期中

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【小题1】

Black boxes are flight recorders placed in an aircraft for the purpose of making it easier to know how the accidents happened in flight.

【小题2】 The flight data recorder catches the information, which can discover whether human error or instrument problems contributed to an accident. The cockpit voice recorder records pilot voices and cockpit sounds.

The black boxes are not black. 【小题3】 The outside is with stripes of reflective tape(反光带). The black boxes are usually placed in the tail of a plane where they are more likely to survive a crash. A flight data recorder is required to store at least 25 hours of flight information. A cockpit voice recorder is required to record at least 2 hours of audio information.

For the black boxes to survive a crash, they are built to be waterproof, fireproof, shockproof, heat and pressure and corrosion resistant(防腐蚀).

【小题4】 It needs special skills to physically bring the black boxes back. Investigators may need to clean and dry the black boxes and download data(数据)from them. It takes time to download and get the information from data. If the storing units go wrong, it will take longer time, either days or months.

【小题5】

A．How is data from black boxes picked up?

B．Do you know black boxes?

C．So, the black boxes are very important to explain to everyone what happened during the flight.

D．They are painted bright orange to help with their recovery after accidents.

E．An airplane actually has two black boxes.

F．It’s not that difficult to pick up the data from black boxes.

Useful Information in Australia

Useful Numbers

All the telephone numbers are useful and free.
Fire/Police/Ambulance—000
Medical Care—1300369359
Telephone information—12455
Taxi—1800421113

Surfing the Internet

With so many Internet tearooms and public libraries, it’s easy to surf the Internet in Australia. Also, it’s very cheap for you to surf the Internet.
Public libraries offer free Internet every day even during public holidays.
Many travel managers provide connection which is cheap or free.

Post Service

All post offices around the country offer post services (服务) so you can receive mails as you travel around the whole country.
Post offices are usually open from Monday to Friday from 9 a.m. to 5 p.m.
It costs 50 cents to send a standard (标准的) letter in Australia.

Public Holidays

On public holidays all shops are closed across Australia, so are banks and post offices.
New Year’s Day—1st January
Australia Day—26th January
Christmas Day—25th December

【小题1】If there is a fire, you can call ________ in Australia.

【小题2】Which is the right time to send a letter in a post office in Australia?

A．At 8:30 a.m. on Tuesday.	B．At 9:30 a.m. on Monday.
C．At 10:30 a.m. on Saturday.	D．At 11:30 a.m. on Sunday.

【小题3】Which one might be open on public holidays?

When you think of a museum, I bet you don't think of a place where children run around. But the Science Museum is different. It's noisy!

You can get to the Science Museum by going on the London Underground from Waterloo on the Jubilee line to South Kensington. When you walk out, take a look around you, and you could see it.

What to bring: at least two bottles of drink for the kids and 10 pounds to spend in the cafes. Entrance is free!

The most interesting part of coming here is to go to the kids' area, the Launch Pad on the 3rd floor. At busy times, you may have to wait in line, but staff will provide science. It should indulge(满足) you as you will learn about science in a funny way. There are also simulators(模拟装置) in the 3rd floor, so think of Floor 3 as a "fun floor".

If you want to learn about the museum, then go to the ground floor. They have some things which will interest you.

Overall, it's a fun experience for the kids and you may enjoy it too. It's also free to get in!

【小题1】How is the Science Museum different from other museums?

【小题2】Paragraph 2 is mainly about ________.

A．how to get to the Science Museum

B．when to visit the Science Museum

C．what to bring to the Science Museum

D．how to plan a trip to the Science Museum