3. 解析:选D。考查dare的用法。dare既可作情态动词也可作实义动词，作情态动词时，其后接动词原形，其否定形式是在dare后加not;作实义动词时，用助动词否定，其后常接动词不定式。因此只有选项D正确。

2. 解析:选C。考查avoid的用法。avoid后接动名词作宾语，而不接不定式。老人应该是避免被伤到，所以应是“avoid being hurt”，答案为C。

5. Mr Wu often tells jokes when we get bored, making the class lively and interesting.

提升练习

4. Her performance in college was excellent. As a result, she has got a satisfactory job.

3. I don?t know what is wrong with me; I keep breaking things today.

2. China has made great progress in modern medical science.

B.1.as a result of　 2. so　 3.As a result 4. as a result of5.As a result

7. revise 8. immediately 9. scientific 10. nervous