in a long queue we waited for the store to open to buy a New iPad.A. StandingB. To stand

问题补充：

in a long queue, we waited for the store to open to buy a New iPad.

A. Standing

B. To stand

C. Stood

D. Stand

答案：

(答案→)A. Standing

B. To stand

C. Stood

D. Stand

解析：本题非谓语动词。句中We和stand构成主动关系，故使用现在分词作状语。具有：排着很长的队，我们等待商店开门买新的iPad。