A 各种形式

现在时

must+现在式：

He must live here．

他一定是住在这里。

或must+进行式：

He must be living here．

（译文同上。）

过去时

must+完成式：

He must have lived here．

他一定在这里住过。

或 must+ 完成进行式：

He must have been living here．

他当时一定住在这里的。

注意 must的各种过去式表示推断和 had to相当于 must表示义务的区别。

must不能用于表示否定的推断（参见第159节），一般也不用于疑问式，除非是对含有must的推断句提问：

—There is a lot of noise from upstairs．It must be Tom．

—Why must it be Tom？Other people use that flat．

—楼上喧闹的声音很大。一定是汤姆弄的。

—为什么一定是汤姆呢？那套房子里也有别人。

B 例句

He has a house in London and another in Paris，so he must be rich．

他在伦敦有一栋房子，在巴黎又有一栋房子，可知他一定有钱。

—I've had no sleep for 48 hours．

—You must be exhausted¹．

—我已经48小时没睡觉了。

—你一定筋疲力尽了。

He develops his own films．That must save him a lot of money．

他自己冲洗照片。那样肯定为他节省了很多钱。

I keep meeting him on the bus．He must live／must be living near by．

我接连在公共汽车上碰到他。他一定就住在附近。

The police are stopping all cars．They must be looking for the escapedprisoner．

警察命令每一辆车都停下来（接受检查）。他们一定是在查找逃犯。—What explosion²？I didn't hear any．

—You must have heard it！The whole town heard it！

—什么爆炸声？我一点也没听见。

—你一定听见了！全城人都听见了！

He must have taken sleeping pills³ last night．He didn't wake up till lunch time．

他昨晚一定吃了安眠药。他一直到吃中午饭的时候才醒来。

—I waited under the clock！

—So did I，but I didn't see you！We must have been waiting under differ- ent clocks．

—我在大钟底下等的！

—我也是，可我没见到你！一定是在两个不同的钟底下等的。

—It was a head-on collision，but the drivers weren't hurt．

—They must have been wearing their seat belts⁴．

—这次车祸中肇事车辆迎头相撞，但两个驾驶员都没伤着。

—他们肯定系了安全带了。