根据句意及首字母提示补全单词。

1. Take the e               to the second floor and you will find the bookstore.

2. —Excuse me. Do you know where I Can e               money?

    —Sure. There is a bank on the second floor.

3. Could you tell me how to g               to the post office ?

4. We decide to talk to some students a               why they go there

5. I prefer h       outside to staying at home.

6. When I go into stores, I always s               too much money.

7. Go out of' the door and t              a right turn

8. They have organized games and the staff d              up as clowns.

0.5 mol Na₂SO₄中所含的Na⁺ 离子数约为：

A．3.01×10²³

B．6.02×10²³

C．0.5

D．1