The boy is lying on the ground at the aeroplane in the sky.A. lookedB. lookingC. lookD.

问题补充：

The boy is lying on the ground, at the aeroplane in the sky.

A. looked

B. looking

C. look

D. to look

答案：

A. looked

(答案→)B. looking

C. look

D. to look

解析：考查分词做状语。Look与the boy构成一个主动关系，且与lie同时发生，所以使用doing的形式。句意：那个男孩躺在地上，看着天上的飞机。