Mr.Smith ___here for about two hours.

来源：百度知道 编辑：UC知道 时间：2024/05/15 14:05:17
Mr.Smith ___here for about two hours.
A.has left B.left from C.went away from D.has been away from
They have been skating __.
A.for three hours ago B.since three hours ago
C.three hours ago D.since three hours
应该选哪个？为什么 ？ 请把每道题的答案做下分析

1.D 抓住关键 for about two hours,用完成时.
2.B
完成时中
for 后面跟一段时间词( three hours,a year,a month....)
而since 后面跟时间状语(three hours ago,a year ago,a month ago)注意区别.

d

b

1. D for+一段时间要用现在完成时,而且还要时延续性动词
2. B 排除法A.D语法错误,C的话时态要用一般过去

第一题选D ,因为是表示延续的时间。

第二题选A, 这是完成进行时，表示延续的动作。

>A mr smith (has left)here for about two hours.
B mr smith (left)for about two hours.
C mr smith (went away) for about two hours.
D mr smith (has been away) for about two hours.

A they have been skating (for 3 hours).
>B they have been skating since 3 hours ago).

d for加一段时间表示时间延续用完成时

b since+....ago for+一段时间