$-2$的相反数是(    )。

完成对话

A: Hey, you look unhappy. ____?

B: I need some ____. What should I get for my father's birthday?

A: How about a belt?

B: No, it's too boring.

A: What about a tie?

B: Oh no, it's so____ style.

A: Well, why don't you buy an iPhone 6？

B: Oh, my God! It's quite____.

A: Umm... A tennis racket, OK?

B: That sounds____. My father likes sports.

读一读，选出发音不同的一项。

在氢硫酸溶液中加入少量下列物质：①O₂；②Cl₂；③SO₂；④CuSO₄．能使溶液pH值减小的是（　　）

People often lose things____ they're travelling____  ____ they're in a hurry．

人们在旅行中或是匆匆忙忙时经常丢东西。