Passage 17

If you think you have a puncture(漏气), first check the valve(阀门) to make sure air is not leaking from it, by putting spit on the end of it. If the valve is not the source of the leak, remove the wheel from the bicycle and put the tyre off. Be careful not to pinch the inner tube. Remove the inner tube and pump some air into it. Do not use tyre levers for doing this. Then hold it in a bowl of water until you see bubbles coming from it. Or, hold the tube to your ear and listen for air escaping. Dry the tube. Choose a patch which is big enough to cover the hole and the surrounding area. Apply glue to tube before sticking patch down. Before you put the tube back in the tyre, run your fingers over both the inside and outside of the tyre to make sure that whatever caused the puncture is not still there. To replace the tube, put the valve part way through the hole in the rim(轮圈), pump a little air in , and then feed it carefully under the tyre, Push the tyre over the rim and back into position.
Pump up the tyre fully and replace the wheel on the bicycle. Make sure the wheel is positioned in the center of the frame.

1. This passage is intended for someone who________.

A. buys a new bike

B. learns to ride a bike

C. has a flat tyre

D. travels by bike

2.If the tyre leaks, you should first___________.

A. check the valve

B. replace the tyre

C. go to the repairman

D. pump some air into the tube

3.You may examine whether the air is leaking by___________.

A. removing the wheel from the bike

B. drying the inner tube

C. running your fingers over the inside of the tyre

D. listening for air escaping

4.From the context we may see that a lever is a tool which can be used to ___________.

A. push the tyre back into position

B. take out the inner tube

C. remove the wheel from the bike

D. replace the wheel on the bike

5.The passage implies that if the air leakage came from the valve,__________.

A. you should still need to examine the inner tube

B. it would be unnecessary to do anything about the inner tube

C. you could solve the problem by putting spit on it

D. there would be no way to solve the problem