( ) 15.Tom might have come to school in time for Professor Brown's lecture,______ .A.if he got up early B.unless he had got up early C.but he got up rather late D.but he had got up so late if 表示虚拟语气,是否用if he had got up early
问题描述：
( ) 15.Tom might have come to school in time for Professor Brown's lecture,______ .
A.if he got up early B.unless he had got up early
C.but he got up rather late D.but he had got up so late
if 表示虚拟语气,是否用if he had got up early
答
这是虚拟语气，表示本应该发生而没有发生的事情
A. if he got up early 则应该跟的是 Tom might come to school in time
你说的改为if he had got up early 则是对的，发生在have come to school之前。
B. unless=if not 意思刚刚相反了，把early改成late
C but 后面跟的是一般过去时态，时态不搭配，和A一样的问题
D 时态正确，没什么问题。
这个句子不一定非要做成复杂句（hypotaxis）， 可以做成并列句（parataxis）
答
这个问题你问了几次了
这个是过去时的虚拟语气,它的形式为
从句,if+were/had done,主句：主语+would/might/+have+done
所以当然选A了