在很多英语单词的词根前加上前缀 “prefixes”，则能使之变为具有全新意思的新词。常见的英语前缀有 “in-、un-、de-、dis-” 等。比如，在单词 “certain 确定的” 前面加上前缀 “un-”，组成形容词 “uncertain”，词义也随之变成了 “不确定的”。英语中还有哪些常用前缀？它们的用法分别是什么？

1. When she was younger, she was very _______ responsible.

a) il-

b) ir-

c) im-

d) de-

2. Yu Yan has travelled the world on her own. She's highly _______ dependent.

a) il-

b) im-

c) un-

d) in-

3. In countries all over the world, it is _______ legal to buy alcohol under the age of 18.

a) il-

b) un-

c) dis-

d) de-

4. Mika's boss is so _______ patient. He wants everything done immediately.

a) in-

b) il-

c) im-

d) dis-

5. Eating my cheese without asking is so _______ honest.

a) un-

b) dis-

c) de-

d) in-

6. She's so clever. That card trick she did was _______ believable!

a) un-

b) dis-

c) im-

d) in-

7. When will this situation ever end? The discussions can't continue _______ definitely.

a) un-

b) dis-

c) im-

d) in-

8. Will scientists ever _______ code the human genome?

a) dis-

b) un-

c) de-

d) in-

答案

1) b, 2) d, 3) a, 4) c, 5) b, 6) a, 7) d, 8) c.