It’s six o’clock in the evening. Helen ________ her homework. (  )

A．doing

B．do

C．is doing

Look at the blind man. He __________ the road, Let's help him. （    ）

A．is crossing

B．is cross

C．crosses

用所给词的正确形式填空。
【小题1】We should stop _________ (throw) rubbish into rivers.
【小题2】In the past, the Earth _________ (be) clean and beautiful.
【小题3】My brother is __________ (plant) trees in the backyard.
【小题4】The Earth __________(get) sick now.
【小题5】We shouldn’t __________ (cut) down so many trees.

用所给词的适当形式填空。
【小题1】Tom often ___________（watch）TV on Saturday evening.
【小题2】Look! The girl ___________（swim）with her mother.
【小题3】The boy usually ___________（go）to school on foot, but last Friday he ___________（ride）a bike.
【小题4】The Greens ___________（travel）to Hong Kong next week. They ___________（stay）there for three days.
【小题5】We ___________（have）an English test yesterday morning and we all ___________ （not feel）well.

Write (T) or (F), and correct on the line: What do they doing now? _____________