3. 解析：选D。后半句“I have something important to attend to”暗示了前半句是委婉拒绝。C项太直接，不符合英美人的习惯。

2. 解析：选C。every other line 每隔一行。类似短语还有：every three days 每三天；every five months 每五个月；every other day 每隔一天。

5. Our English teacher often talks to us about the significance of English learning.

提升练习

4. Ten runners will compete for the gold medal in the 100?metre race.

3. London will host the 2012 Olympic Games.

2. How many Chinese athletes will take part in the next Olympic Games?

3. made contributions to　　 4. in honour of　　　 5. make way for

5. requirements

4. attractions

3. glorious