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