Fuel oil tanks must be fitted with () that can be closed rapidly and remotely in the event of an emergency such as a fire.
A. stop valves
B. non-return valves
C. quick closing valves
D. relief valve
查看答案
门式刚架结构所用钢材的屈强比、伸长率以及应变等力学性能应满足一定的条件,是为了()。
A. 在弹性范围内工作
B. 使结构有足够的强度
C. 使钢材能充分发挥其塑性变形
D. 是结构具有足够的抗震性能
油松和黑松的冬芽分别为()色。
A. 褐、黑
B. 褐、白
C. 黑、白
D. 黑、褐