---i'm sure Tom will pass the final examination

问题描述:

---i'm sure Tom will pass the final examination
---i think so .he___for it for months
A.had been preparing
B.was preparing
C.is preparing
D.has been preparing
答案为什么是D呢?

翻译:--我确信汤姆将会通过期末考试.--我有同感.他为它(这次期末考试)准备了好几个月了.此题考查各种时态的特征和区别.1.A为过去完成进行时,表示某一动作/状态从过去开始,一直延续到另外一个过去的时刻为止.B为过...