∵A⊆B,且θ是锐角
∴sinθ=12,
∵sin30°=12,
∴α=30°.
故答案为:30°
The ______ the young man left on us is that he was a respectable family. [ ]
A. sight
B. appearance
C. impression
D. expression
某五层现浇钢筋混凝土建筑结构的施工,其主体工程由支模板、绑扎钢筋和浇筑混凝土3个施工过程组成,每个施工过程在施工段上的延续时间均为5天,划分为3个施工段,则总工期为()天。
A.25
B.40
C.85
D.100