生活饮用水水质标准(GB5749—1985)中要求锌的含量范围是()。
A、不大于1.5mg/L
B、小于1.0mg/L
C、不大于5.0mg/L
D、小于1.5mg/L
参考答案:B
下列图示的实验中涉及到化学变化的是
A.检查装置的气密性
B.读取水的体积
C.点燃酒精灯
D.称量氯化钠的质量
We wanted to know _____. [ ]
A. where did he live three years ago
B. where he lived in three years before
C. why he cried so sadly
D. how soon he will come back