When he saw a wallet on the playground heat once . A. picked it up B. gave it up. C. pic

问题补充：

When he saw a wallet on the playground , heat once .

A. picked it up B. gave it up. C. picked up it.

答案：

解析：pick up捡起;give up放弃,交出.在动词+副词的短语中，作宾语的是代词it 或 them，要用代词的宾格，并且必须放在动词和副词之间。本句意思是“当他看见地上的钱包时，他立刻把它捡起来。”故A。