在扭转荷载作用下,杆件由于支承条件或荷载条件的不同,其截面不能完全自由地产生翘曲变形,这种翘曲变形受到约束的扭转称为()扭转。
A.翘曲
B.自由
C.条件
D.约束
参考答案:D
If city noises ___ from increasing, people ___ shout to be heard even at diner.
A.do not keep; will have to
B.are not kept; have
C.are not kept; will have to
D.do not keep; have to
折叠式消防救援担架的承重为()kg。
A.50.0
B.80.0
C.100.0
D.120.0