根据对话内容，从方框内所给的七个选项中选出五个，使对话完整。
a. I'll watch it.
b. What are you doing?
c. I'd rather watch some other programs.
d. Don't worry.
e. How was your science exam?
f. Which teams are playing?
g. Is there a football match onTV tonight?
Richard: Hi, Simon. ____
Simon: Not too good.
Richard: Well, the term exam is always more difficult. ____You'll certainly do better next time.
Simon: But unluckily, I've never done well in the science exam.
Richard: Come on, Simon! Let's talk about the football match tonight. It is much more interesting.
Simon: ____
Richard: Yes. It's between the Chineseteam and the Japanese team.
Simon: Er… ____
Richard: Why? Everybody knows you area football fan.
Simon: The Chinese team has always played badly in the important matches, just as I have done in the importan texams.
Richard: Well, I think the team is making good progress. ____
。为使弹簧振子的振幅最大,则电动机的转速应为( )