问题补充：
Doing experiments can be interesting, and you may try the following experiments at home. Make sure that you’ll do them with an adult.
【小题1】How many experiments are there in the pictures?A．Six.B．Five.C．Three.D．Two.【小题2】The following are the instructions on how to do “Step 2” in these experiments. Which one is the right order?
a. Pour 3/4 of the water away.
b. Put a balloon on the bottle.
c. Put the bottle in a bucket of hot water. The air rises into the balloon.A．a, b, cB．a, c, bC．b, a, cD．c, a, b【小题3】What can you see in the bottle at last in Experiment A?A．Some ice.B．Some water.C．Some ice and water.D．A cloud and some water.【小题4】What will happen to the balloon in “Step 3” in Experiment C?A．It will be bigger.B．It will be broken.C．It won’t change.D．It will be in the bottle.C
答案：
(答案→)C
解析：短文属于图表类阅读。实验空气遇冷遇热的变化。
【小题1】细节理解题。从图片中可以看出，共有三个实验。
【小题2】综合理解题。通过认真看图分析，可以得知。实验A的第二步是倒出一些水，以便于有形成云的足够的空间；实验B的第二步是把瓶子放在热水中，以便于使瓶中的空气遇热上升进入气球；实验C的第二步是把气球放在瓶子上。
【小题3】细节理解题。从实验A的第④步“…there is a cloud”可以看出瓶中产生了云，当然里面还有原来的水。
【小题4】推理判断题。因为“cold air falls”可知，瓶中的空气遇冷要下降，气球也随之下降进入瓶中。
