Those letters are _____ to the countryside right away.
问题描述：
Those letters are _____ to the countryside right away.
A.to be sent B.sending C.to have been sent D.sent
为什么选A
答
right away “立刻,马上”,要用一般将来时态,排除B、C、D；be to do就可以用来表示将来,同时这里还要注意使用被动语态.