凸轮压力角的大小与基圆半径的关系是()
A.基圆半径越小,压力角偏小
B.基圆半径越大,压力角偏小
C.基圆半径越小,压力角为零
D.基圆半径越大,压力叫趋向负
参考答案:B
中国社会的最主要次级集团是下面哪一项()
A、宗族
B、宗教
C、自由结社
D、种姓
Some people who don’t like to talk much are not necessarily shy; they _____ just be quiet people.
A.must
B.may
C.should
D.would