外科休克的主要病因有()。
A.损伤
B.过敏
C.大出血
D.脑外伤
E.严重感染
参考答案:C, E
.
--- I think this accident happened for many reasons.
--- Richard is partly to blame, __________way you look at it.
A.what
B.which
C.whatever
D.whichever
高度为H的挡土墙,墙背直立、墙后填土面水平。填土是重度为γ、内摩擦角φ=0、粘聚力为c的粘土,墙与土之间的粘聚力为ca,外摩擦角δ=0。若忽略拉裂的可能性,试证明作用于墙背的主动土压力为: