当我们放寒假过春节时，澳大利亚的小朋友在（    ）

根据下面的对话内容，从对话前的选项中选出最佳选项填入空白处，将代号填入空白处。选项中有一个多余选项。

A: It's very late. Are you still on the computer?
B: Well, yes. ____ 
A: What kind of e-mails?
B: Some are messages from my friends and some are from the relatives.
A: Do you have to write them back right away?
B:____  Usually people want a quick reply.
A:____ 
B: I've already had 40 people's addresses in my address book!____ 
A:____  E-mail is really very convenient(方便的).

在空间直角坐标系中，已知点P（x，y，z），下列叙述中正确的个数是（　　）

①点P关于x轴对称点的坐标是P₁（x，﹣y，z）； 

②点P关于yOz平面对称点的坐标是P₂（x，﹣y，﹣z）；

③点P关于y轴对称点的坐标是P₃（x，﹣y，z）； 

④点P关于原点对称的点的坐标是P₄（﹣x，﹣y，﹣z）．

读世界主要宗教分布图，完成下表。