干气密封受到外力干扰后间隙减小的变化是()。
A、气体剪切率增大
B、气体剪切率增小
C、螺旋槽开启间隙的效能增加
D、螺旋槽开启间隙的效能减小
参考答案:A, C
You’d better not phone the manager between 7 and 8 tomorrow evening; he ________ an important meeting then.
A.will have
B.would have
C.will be having
D.will have had
具有第一类精神药品处方资格的是()
A.执业助理医师
B.执业医师
C.实习医师
D.执业药师
E.经培训,考核合格的执业医师