补全对话。从对话后的选项中选出能填入空白处的最佳选项。（其中有两项是多余的。）
A: Welcome to I COOL, YOU COOL, madam. How can I help you?
B:____ .
A: This way, please. These are the latest fashion.____ 
B: It looks cool. But I don't like bright green.
A: We've got many colors: pink, grey, dark red and yellow.____ . 
B: Pink. Could you show me the light pink one?
A:____ . And it's very thick.
B: I like it.____ .
A: It was 100 dollars but now it is only 50 dollars.
B: That's a great price. I'll take it.

2012年6月2日新疆科克苏湿地进行第四次生态补水，补水约46万米³，46万米³用科学记数法表示为（  ）

计算：$\frac{12}{m^2-9}$+$\frac{2}{3-m}$+$\frac{2}{m+3}$