This is a street crossing. There are red and green lights at

This is a street crossing. There are red and green lights at each corner. Drivers must watch the lights carefully.
When there is a green light, the cars may go. When there is a red light, the cars must stop. They must wait until the red light changes to green. Then they can go on. Sometimes the cars want to make a right turn or a left turn. They can make a right turn when the light is green or red. But they must wait until the green light is shining if they want to turn left.
Some people are color-blind(色盲). They can not tell the difference(不同) between the red and green lights. These people must not drive, or there will be accidents. We must keep our streets safe.
小题1:Drivers must watch _____ carefully at each corner.
A.green lights B.red lights C.both green lights and red lights
小题2:When there is a red light _____ .
A.the cars must stop B.the cars may go on C.the cars may make a left turn
小题3:Cars can make a right turn when _____ .
A.there is a red light B.there is a green light C.there is a red or green light
小题4:Color-blind people may have accidents because _____ .
A.they can’t see cars
B.they can’t see the lights
C.they can’t tell the difference between the red and green lights
小题5:According to (根据) the passage _____ must not drive.
A.young people B. color-blind people C.old men