按照采煤机的牵引传动方式的不同可分为液压牵引滚筒式采煤机和电牵引滚筒式采煤机。
参考答案：对
—Where were you at eight yesterday evening?
—______.
A．I saw you at eight yesterday evening
B．I am helping my mother cook
C．I will go to my friend’s home
D．I was in the kitchen at that time
A．75 km/h
B．70 km/h
C．90 km/h
D．72 km/h
