五、冠词用法讲练
（一）冠词的位置
1) 在名词词组中，冠词一般放在最前面。例如：
the last few days      a really good concert
2) 名词词组里如果有all, both, exactly, just, many, quite, rather, such, what等词，这类词可以放在冠词之前。例如：
all the time    both (the) brothers
exactly the wrong colour  just the right place
quite a nice day    rather a mess
such a funny story
3) 和as, how／however, so, too连用时, 形容词放在冠词之前。例如：
He’s not so big a fool as you think.
She’s as clever a girl as you’re ever likely to meet.
This is too heavy a bag for me to carry.
How large an armchair did he have?
However tiring a day she may have, she never loses her good humour.

（二）不定冠词 (Indefinite Article)
1) a／an表示“任何一个(类)”，只能用于单数可数名词前。例如：
We are having a committee meeting this afternoon.
a／an不用于不可数名词前。例如：
There will be discussion and argument at the meeting.
He drinks milk every day.
2) 不可数名词用作可数名词时，可用a／an。例如：
I’ve just bought a lovely big Danish cheese.
I don’t like cheese.
She was inspired with a new courage.
She showed great courage.
3) 用于表示价格、速度、比率等名词前，如five pence a kilo, sixty kilometers an hour, four times a day等。
4) 用于下列这样的固定短语中。如a couple, a dozen, half a dozen, a hundred, a lot of, a great many, a great deal of, a large amount／quantity of, a good number of 等。
I’ve done a great deal of work today. (不可数)
What a large number of books you have! (可数)
It’s a good five miles(=at least five miles, perhaps mote) to the station.
    5) 以元音开头的单词前不定冠词用an, 如：an apple, an egg, an item, an old man, an umbrella, an hour; 以辅音开头的单词前不定冠词用a university student, a humorous man。

EXERCISE l
A. Put a or an before each of the following:
1.         motel (汽车游客旅馆)  2.         unusual approach
3.         honest boy    4.         awkward situation
5.         exit (出口)    6.        urgent message
7.        unique opportunity   8.        extremely exciting film
B．Translate the following into English：
1．一座新办公楼     2．一位旅行社代理人 
3．一位美国科学家     4．一天的郊游
5．一张印度邮票     6．一次心脏病发作   
7．一个先进国家     8．一个有意思的剧本

EXERCISE 2
Fill in the blanks with a or an where necessary:
1.         Telephone is         very important means of communication.