Lotsofrescueworkerswereworkingaroundtheclock，

問題詳情：

Lots of rescue workers were working around the clock，________supplies to Yushu，Qinghai Province after the earthquake.

A．sending                  B．to send

C．having sent               D．to have sent

【回答】

A

知識點：非謂語動詞

題型：選擇題