书名：Longman Preparation Series for the New Toeic Test Intermediate
版本：4/e
题目：
The new course ___ by the 5th of June. It's too bad that you don't
get back on that day.
(A) will start
(B) will be starting
(C) will have started
(D) will have been starting
疑问: 为什么是C而不是A或D
题目： The class ___ for three weeks by the time you join us. I'll fill
you in at that time.
(A) will run
(B) will be running
(C) will have run
(D) will have been running
疑问：为什么是D而不是C
谢谢!