题目内容
--What did he ask on the phone just now?
--He wanted to know ___________.
A.when the meeting will start B.what I was going to say at the next meeting
C.how long would the meeting last D.who is the host of the meeting
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.