若要提高螺纹联接的自锁性能,可以().
A.采用牙形角大的螺纹
B.增大螺纹升角
C.采用多头螺纹
D.增大螺纹螺距
参考答案:A
—However busy he is, he will some time for exercise every day.
—No wonder he is always so energetic.
A.put away
B.turn out
C.bring in
D.set aside