对于不锈耐酸钢容器，试验用水的氯离子含量不应超过（）。
A．10×10-6
B．15×10-6
C．25×10-6
D．30×10-6
参考答案：C
我国热带雨林主要分布在（ ）
A．海南岛、西双版纳
B．广东、广西
C．台湾、福建
D．东北、西北
At first he refused to admit he had stolen but when he was shown the videotape（录像带）he ________ and admitted everything.
A．broke up
B．broke away
C．broke down
D．broke in
