书法作品有“飘若浮云，矫若惊龙”美称。这一作品的首书者是（     ）

$\frac{5}{9}\times \frac{7}{5}$ ____ $\frac{5}{9}$          $\frac{6}{7}÷3$ ____ $\frac{6}{7}$       $\frac{3}{4}\times 2$ ____  $\frac{3}{4}÷\frac{1}{2}$

试分析计算回答：

A: Have you learned Topic 2, Unit4?  

B: No, not yet. We will begin to learn it next week.

A: But we've learned it. It's about some ____ like Edison, a great American inventor.

B: I have read about Edison in a book, so I know ____ about him.

A: Really?

B: Yes. He invented a lot of things. And they all have ____ the world.

A: I know he was born in 1847, and died in 1931.

B: So he has been ____ for more than eighty years.

A: Yes, but we can remember him every day.

B: Sorry, I don't understand ____ you mean.

A: Do you give your friend a call every day?

B: Yes. Oh, I see. Edison invented the telephone.