带式除铁器是由电磁铁、机架、驱动电机、减速机、()、弃铁皮带、支撑托辊、冷却风机等组成。
A.主、从动滚筒;
B.改向滚筒;
C.增面滚筒;
D.拉紧滚筒。
参考答案:A
The film __________ for ten minutes when we got to the cinema.
A. had already been on
B.had already begun
C.have already been on
D.have already begun
股票发行方式按发行对象的不同可以分为()发行与()发行。