A:For example
B:After all
C:So far
用方框中所给的词填空
cold education postman heat full-time
① Are these all ours? ____ A. It is Zhang Peng's.
② Whose is it? ____ B. Yes,it is.
③ Is this yours?____ C. Yes. they are.
请用正确的数字和符号填空:(1)3个硫酸根离子____;
(2)2个氯分子____。
把图3中各电路元件接成串联电路.