推力球轴承装配时，、一定要使紧圈靠在（）的平面上。
A.转动零件
B.静止零件
C.任意零件
D.大的零件
参考答案：A
David said that it was because of his strong interest in literature＿＿he chose the course.
A．that
B．what
C．why
D．how
压电性
