在困难条件下，对次承受静力荷载为主的钢筋，闪光对焊下焊的环境气温可适当降低，最低不能低于（）。
A.－10℃
B.－5℃
C.5℃
参考答案：A
属于时间管理基本程序的是（）。
A.评估
B.列单
C.分类
D.排列
E.分配
The long-run production decision differs from the short-run production decision in that:（）
A. variable costs can be changed in the short run but not the long run.
B. variable costs can be changed in the long run but not the short run.
C. fixed costs can be changed" in the long run but not the short run.
