Question

—Where is my pen?
—I _________ it on the desk, but I don’t know who _________ it away.

A．put; has taken

B．put; took

C．have put; took

D．have put; has taken

Answer 1

A

考察时态。句意：我的钢笔在哪儿？——我放在桌子上了，但是我不知道谁拿走了它。可知前文叙述的是过去发生的动作，下文强调已经完成的动作，故前文用过去时态，下文用完成时态。Put过去时与原形一样，故选A。