题目内容
In Western culture, “Black ____________(星期五)”, sometimes represents an unlucky day.
轻松课堂单元测试AB卷系列答案
小题狂做系列答案An INTERESTING experiment
It takes a little skill to do this experiment, but the result is truly SURPRISING.
What do you need? ? Several rubber balloons ? Wooden skewer（木签） ? Vegetable oil ? Paper towel |
| Step l Blow up a balloon, let some of the air out of it, and tie it closed. |
| Step 2 Rub some oil on skewer with paper towel. | |
| Step 3 Gentle twist（搓捻）and push skewer into end of balloon opposite the knot. If balloon pops（爆 炸），go back to Step 1. | |
| Step 4 When skewer is in balloon, slowly twist and push it out of balloon near knot. | |
What will happen? |
| ____▲______ The balloon does not pop, even though it has a skewer in it. |
Why won’t it pop? | ? Rubber is made out of long chains of molecules （分子）. ? The skewer pushes these molecules aside. ? The molecules mix with the oil and they stick together tightly. ? The oil on the skewer seals the hole and air cannot get out. |
1.Which is the most suitable word for “ ▲ ”?
A.Topic B.Result C.Step 5 D.Reason
2.What can we infer（推断）from the passage?
A.It’s easy to push a skewer into and out of a balloon when doing the experiment.
B.You’d better blow as much air as possible into a balloon to make it big enough.
C.There’s no need for you to use the oil and paper towel while doing the experiment.
D.It’s hard for the air to get out of the hole as molecules and oil stick together.
阅读下面短文，并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。
注意:请将答案写在答题卡上相应题号的横线上。每个空格里只填一个单词。
Many of us have had this experience: we lie down in a bed other than our own, perhaps at a friend’s house or in a hotel room, and find it difficult to fall asleep.
Why does it happen?
A new study shows one reason is what the scientists call “first night effect”. They believe that one side of the brain acts as a “night watch” to warn us about possible dangers. It prevents us from getting to sleep on the first night in a new environment.
For the study, 35 young volunteers were asked to sleep in a sleep lab for several days as researchers watched their brain activities.
According to the researchers, on their first night, the left brain was more active than the right brain and people had a hard time sleeping. However, the left brain activity decreased(降低) as days went by, falling even to the point of complete calm. In this process, the volunteers got better and better sleep experience.
The findings show that the different rhythms(节奏) of the sides of the brain affect our sleep. When the two sides work differently, the balance between them is broken. So the brain can’t relax and is sensitive(敏感的) to anything strange around.
“At some level, the brain is continuing to work, even though you don’t realize it,” US professor Jerome Siegel told Smithsonian Magazine. “If something unusual happens, you can be alert(警惕的)”.
More surprisingly, this is like the way some animals sleep. Whales, dolphins, and many birds can sleep with half of their brain while the other half stays awake, with one eye staying open.
The researchers think that it is the result of evolution(进化) and works to protect us in possibly dangerous environments.
If you have ever had first night effect, researchers advise you to bring your own pillow or sleep in a room similar to your bedroom next time you sleep away from home.
First night effect | |
People’s possible experience | Many people have 1. getting to sleep on the first night in a new environment. |
The findings of the study | ?First night effect forces us to stay awake as one side of the brain is alert to possible dangers. ?As days go by, people’s sleep experience 2. as the left-brain activity falls. |
The explanations to the findings | ?On the first night in a new environment, people’s left brain is more active than the right brain and that 3. the balance between them. ?Our brains continue to work without being realized at night so that we can be sensitive to anything unusual. ?Some other animals sleep in the similar way, which is thought to be 4. by evolution. |
5. from researchers | Bring your own pillow or sleep in a bedroom that looks like yours. |