某实验室用30克氯酸钾和5克二氧化锰的混合物加热制取氧气，反应一段时间后，冷却称量，得到25．4g剩余固体物质。试计算：

①生成氧气的物质的量为      摩尔。

②参加反应的氯酸钾的物质的量为       摩尔。（根据化学方程式列式计算）

— When will you come home for dinner? I'll prepare it for you.

一 Don't _____ it. I'll eat out with my friends.[ ]

A. care about

B. worry about

C. bother about

D. talk about