问题：
Look! Some children are ________. They are going to visit Disneyland by bus.
[ ]
A. playing computer games
B. sweeping the floor
C. revising for a test
D. waiting for a bus
Look! Some children are ________. They are going to visit Disneyland by bus.
B. sweeping the floor
C. revising for a test
D. waiting for a bus
[ ]
A. playing computer games B. sweeping the floor
C. revising for a test
D. waiting for a bus
参考答案：