Question

Some children were seen _______in the garden all the morning. It must have been _______who picked the flowers.

A．playing; they

B．to play; they

C．playing; them

D．play; them

Answer 1

A

考查非谓语动词与人称代词。句意：一些孩子被看到整个上午都在花园里玩。肯定是他们拔了这些花。现在分词做状语表示句子主语正在进行的伴随性动作。下文人称代词为从句的逻辑主语，故需用主格形式，选A。