In the past three years ,he ____the country twice.A.visited B.is visiting C.had visited D.has visited选什么呢,为什么?C和D怎么判断?
问题描述:
In the past three years ,he ____the country twice.
A.visited B.is visiting C.had visited D.has visited
选什么呢,为什么?C和D怎么判断?
答