We would be most thankful if you could extend this favor to us and agree () 50% by L/C and 50% by D/P at sight.
A. with
B. upon
C. at
D. to
一个物体的平面任意力系平衡方程,最多只能求解()个未知参数。
A. 1
B. 2
C. 3
D. 4
下列传动中,传动效率最低的是()
A. 齿轮传动
B. 蜗杆传动
C. 链传动
D. 带传动
观看淫秽音像制品中的裸体男女,并获得性的满足,不属于()