They are taught by their superiors that a soldier who ______ his post in time of war is to be shot.

A．deserts

B．deflects

C．detains

D．threw

汽缸体上、下平面在螺纹孔口周围凸起通常是由于（）

A.装配时螺栓扭紧力矩过大，或装配时螺纹孔中未清理干净

B.曲轴轴承座孔同轴度偏差增大，或是受到整个汽缸体变形的影响

C.或是由于曲轴轴承座孔处厚薄不均，铸造后残余应力不均衡，在使用中引起变形

D.在高温下拆卸汽缸盖