by, during, over, through, within, upon, till
9)Scientists say that it may be five years before it is possible to test this medicine _______ on human patients. before: 过了多久以后才… “五年 以后才会在人体上做试验。
1) He didn’t answer ____fear for of hurting her feelings.
for: 因为;由于某事物 多用于表示内 在的、心理的原因。 at 2) I’m much pleased ____your arrival. 多用来表示感情上的原因,常和表示 一定感情的词连用
8)They are going to have a good rest during _______the summer holidays. through: 从开始到结束,他们打 了一整夜牌。
during: 在…期间,他们打算在暑 期好好休息。
in, on, from, at, until, for, since, after, before
since, 自从…以来到现在,和完 成时连用。另外,since 还可以用 作副词,表达同样的意思。
in, on, from, at, until, for, since, after, before
by, during, over, through, within, upon 2)She went to Nanjing last May,and she after month. came back ____a after +时间常常和过去时连用,表 示一个时间点。如:after school, dinner, 3pm 等。