检测水样中的“三氯”，在采样前应在采样容器中加入的水质保存剂是 A: H#$IMG0$#SO#$IMG1$# B: Na#$IMG0$#CO#$IMG3$# C: NaHCO#$IMG3$# D: Na#$IMG0$#SO#$IMG3$# E: NaCl

下列哪个是大气中的二次污染物（） A: SO#$IMG0$# B: H#$IMG0$#S C: CO#$IMG0$# D: O#$IMG3$# E: NO

【单选题】It is going to be fine tomorrow, ______. A. So is it B. So it is C. So it does D. So does it A. So is it B. So it is C. So it does D. So does it

It is impossible for little children to do much work in a short time. A: so; so; such B: such; so; such C: so; such; such D: such; such; so

It’s so vast, so deep, so 1___________.

-- David has made great progress recently. A: So he has; so you have B: So he has; so have you C: So has he; so have you D: So has he; so you have

If you give up the plan, ____. A: so will they B: so they do C: they will so D: so did they

Wow. It is rather hot today. Yes. __________yesterday. A: So it is B: So was it C: So is it D: So it was

-He said he enjoyed the quiet life of the country. -__________ and __________ . A: So did he; so did I B: So he did; so did I C: He did so; I did so D: Did he so; so I did

I heard him ___. A: say so B: says so C: saying so D: said so