from 2 o'clock/since 2 o'clock

在使用这两类介词短语时,要注意以下三点:

A. from 2 o'clock (today) 可与不同的动词时态连用, 而 since 2 o'clock 一般只与现在完成时或现在完成进行时连用:

1. I'm on holiday from 30 June. 我从6月30日开始休假。

2. I wrote the letter from two o'clock... 我从两点钟起写信……

3. I shall be with you in New York one week from today. 从今天起我将与你一起在纽约呆上一周。

4. I've changed my address since last year. 从去年起我就更换了地址。

B. from...可用于from...to(till/until)结构中：

1. The shop is open from 9:30 until 5:30. 这家商店从9点30分到5点30分营业。

2. The Museum is open from Monday to Friday. 博物馆星期一到星期五开馆。

C. since...着重强调“自从……起到目前动作或状态的持续情况”：

I have been doing it since the day before yesterday. 从前天开始我一直在干这个活儿。请做下面的英语试题： I haven't seen her ____ then on. A. from B. since C. after D. by