科学规律
参考答案：
科学规律是尽可能精确表达、揭示自然界某种重复性规则的陈述。
— The manager says the meeting will be cancelled.
— _______She just means it will be put off. [ ]
A. Forget it.
B. Good idea.
C. It's my guess.
D. You're missing the point.
供乙炔使用的器材都不能用银和含铜量超过（）铜金制造。
A.50%
B.60%
C.65%
D.70%
