当预测10天内的室外平均气温低于+5℃，或当日最低气温低于（）时，砌筑施工属于冬期施工阶段。
A.-10℃
B.-5℃
C.-3℃
D.0℃
参考答案：C
This passage has too many long sentences. I' m afraid they will be hard for most of the students.
Could you help to _____ them?[ ]
A. mix
B. take
C. destroy
D. simplify
以下属于套利种类的有( )。
A．跨期套利
B．跨商品套利
C．跨市套利
D．期现套利
