用括号内所给动词的适当形式填空。

1. My father _____ (not listen) to the radio at the moment.

2. Tom _____ (write) a letter to his friend these days.

3. —What's your brother doing?

    —He _____ (clean) his new car.

4. Let's _____ (shop) for the coming New Year.

5. What can you _____ (see) in the picture?

世界上最主要的混合农业是[ ]

A、蔗、果、桑、鱼混合农业

B、水稻与牲畜混合农业

C、谷物与牲畜混合农业

D、种植小麦与牧羊混合农业