1.A:l've already collected 30 books on this topic.
2.A:I got the top score in the mid-term exam.
B You're incredible.
2.ball n. 球；球形物；正式的舞会
get the ball rolling 使事情开展起来
A:Let's put on a performance at the beginning of the semester to raise some money for the children's hospital.
B:A good idea. And that will get the ball rolling .
for fun 为了好玩
例句：I'm going to Chicago on business and somebody said you were the right person to talk to about what I can do there for fun.
make fun of 取笑，嘲弄
例句：Little children occasionally like to make fun of others．
4.green adj. 绿色的；青色的；无经验的 n. 公共草地
be green 天真，没有经验（同be as green as grass）
例句：You can't expect Mary to do business with these guys; she is only eighteen.