Lesson 129 Seventy miles an hour时速70英里
【课文详注 Further notes on the text】
1．Where do you think you are?你认为你现在是在哪儿？
do you think 是用在非凡疑问句中的插入语，用来征询见解或表达看法。因为句中插入语已经是疑问式，主谓倒装了，所以you are的位置不能再对调了。插入语一般是对句子加一些附加的解释，在句子中作独立成分。常用来作插入语的结构有I hope, I think, I'm afraid, you know等。插入语可以位于句尾或句中，有时也可出现在疑问句中。
2．must have been doing sth.,一定/准是在做某事。
这种结构用来表示对过去正进行的事情的推测。下文中的can't have been是 can't have been driving的省略式，在意思上与must have been driving正相反。
3．That's why I didn't see the sign.所以我才没看见那牌子。
why I didn't see the sign作is的表语从句，以why引导的从句用来解释事情的原因。
4．…you'd better take my advice!……你最好还是服从我的劝告吧！
take one's advice是“服从劝告”的意思。
【语法 Grammar in use】
表示猜测和推断的情态助动词must和can't（2）
must与can't不仅能表达对现在和将来的猜测和推断，而且能表达对过去的猜测和推断——这时可用 must have been表示肯定的推断，用can't have been（而不是mustn't have been）来表示否定的推断，如后面跟进行时则表示对过去正在进行的动作的猜测。请看例句：
You must have been driving at seventy miles an hour.
你当时肯定正以每小时70英里的速度行驶。
I didn't see it. I must have been dreaming.
我没看见。我当时一定是在胡思乱想吧。
She can't have been 29.She must have been 36.
她那时肯定不会是29岁，她一定36岁了。
He can't have been reading. He must have been sleeping.
他那时肯定不是在看书，他准是在睡觉。
【词汇学习 Word study】
1．charge v.
（1）罚款；使承受经济负担：
He was charged by the policeman for speeding.
他因开车超速而被警察罚款。
（2）要（价）；收（费）：
The hotel charged them ￡ 900 for one night.
饭店向他们索要900英镑作为住一晚的费用。
（3）指控；指责：
They charged him with murder.
他们指控他犯了谋杀罪。
2．dream v.
（1）做梦；梦见：
He dreamt about his grandmother last night.
他昨天夜里梦见他的祖母了。
Do you often dream at night?
你晚上经常做梦吗？
（2）梦想；幻想：
She dreamed that one day she would be as free as a bird
她幻想着有一天自己能像鸟儿那般自由。
I once dreamed of becoming a famous doctor.
我曾一度梦想着成为一位闻名的医生。
（3）出神；心不在焉；空想：
Don't dream away your life!
不要在想入非非中虚度你的人生。
Sorry, I didn't see the sign. I must have been dream ing.
对不起，我没看见那牌子。我一定是思想开小差了。
3．wave v.
（1）招手；挥手示意：
He waved us quiet. 他挥手要我们别出声。
She waved me goodbye. 她向我挥手离别。
（2）起伏；飘动：
The flag is waving in the wind. 旗帜正在风中飘扬。
She was attracted by the waving sea. 她被那汹涌起伏的大海吸引。
【练习答案 Key to written exercises】
Lesson 130
A
1 He didn't come to work yesterday. He must have been ill.
2 He didn't come to the office this morning. He had to stay a home.
3 I don't think she was Austrian. She must have been German.
4 I lost my pen so I had to buy a new one.
5 He forgot his case so he had to return home.
6 She didn't hear the phone. She must have been sleeping.
B
1. I don't think they were. They can't have been Canadian.
They must have been Australian.
2. I don't think she was. She can't have been Finnish.
She must have been Russian.
3. I don't think they were. They can't have been Japanese.
They must have been Chinese.
4. I don't think they were. They can't have been butchers.
They must have been bakers.
5. I don't think she was. She can't have been a dentist.
She must have been a doctor.
6. I don't think he was. He can't have been a sales rep.
He must have been the boss.
7. I don't think she was. She can't have been seventeen.
She must have been twenty-one.
8. I don't think they were. They can't have been five.
They must have been seven.
9. I don't think he was. He can't have been seventy-six.
He must have been over eighty.
10. I don't think she was. She can't have been fifty-five.
She must have been under fifty.
11. I don't think it was. It can't have been the 17th yesterday.
It must have been the 16th yesterday.
12. I don't think it was. It can't have been Tuesday yesterday.
It must have been Wednesday yesterday.
13. I don't think it was. It can't have been the 19th yesterday.
It must have been the 20th yesterday.
14 I don't think it was. It can't have been cheap.
It must have been expensive.
15 I don't think it was. It can't have been easy.
It must have been difficult.
16 I don't think she was. She can't have been old.
She must have been young.
17 I don't think he was. He can't have been ill.
He must have been tired.
18 I don't think they were. They can't have been listening to the radio.
They must have been watching television.
19 I don't think she was. She can't have been retiring.
She must have been looking for a new job.
20 I don't think they were. They can't have been sitting.
They must have been standing.
在英语中，情态助动词 "must" 和 "can't" 不仅可以用来对现在和未来进行猜测和推断，还可以用来对过去的情况做出推断。这种推断通常是基于现有的证据或逻辑推理，来表达对过去事件的高度可能性或不可能性。以下是对这两种情态动词在表示对过去猜测和推断时的用法的进一步解释：
1. Must have been：
You must have been driving at seventy miles an hour.（你当时肯定正以每小时70英里的速度行驶。），说话人可能根据某些线索（如车速表的读数、目击者的证词等）推断出对方当时驾驶的速度。
2. Can't have been：
She can't have been 29. She must have been 36.（她那时肯定不会是29岁，她一定36岁了。），说话人可能根据对方的外貌、已知的出生年份或其他相关信息来推断出对方的实际年龄。
3. 对过去进行时的猜测：
I didn't see it. I must have been dreaming.（我没看见。我当时一定是在胡思乱想吧。）这里，说话人可能因为错过了某个事件或现象，推断出自己当时可能在做梦或心不在焉。
4. 对过去的完成时的推断：
He can't have been reading. He must have been sleeping.（他那时肯定不是在看书，他准是在睡觉。）这里，说话人可能根据一系列迹象或行为推断出对方当时并没有阅读，而是在睡觉。
在使用 "must have been" 和 "can't have been" 进行过去事件的推断时，我们应该意识到这些推断并不是绝对的事实，而是基于当前最佳可用信息做出的合理假设。随着新信息的出现，这些推断可能会被证实或被修正。
通过对过去事件进行推断和猜测，我们能够更好地理解过去发生的事情，并在缺乏完整信息的情况下做出合理的假设。情态助动词 "must" 和 "can't" 在这种语境下发挥着重要作用，帮助我们构建对过去事件的认识和解释。
在使用这些情态助动词时，我们应该注意语境和逻辑，以确保推断的合理性和准确性。同时，我们也应该意识到推断可能存在不确定性，需要持续关注新的证据或信息，以便调整我们的理解和解释。