急性氟中毒的主要症状不包括
A．恶心B．呕吐C．头痛D．腹泻E．肌肉痉挛
参考答案：C
—I think the Internet is helpful to us.
—_____ It is really good and useful.[ ]
A. I don't agree.
B. I agree with you.
C. I don't think so.
D. They are not OK.
物料管理的特征体现在下述几个方面（）
A、同一性
B、流动性
C、相关性
D、价值性
