KY-250A型牙轮钻机行走二级传动链条单条节数为（）节。
A.48
B.50
C.52
D.56
参考答案：B
--- What are you going to do this weekend ?
--- I’m thinking of finishing _____ the English book bought in Being．One learns English by reading and _______ .
A．to read ; write
B．to have read ; to write
C．having read ; writes
D．reading ; writing
My daughter studies______. She _____goes to sleep before 11 o’clock at night.
A．hard, hard
B．hard, hardly
C．hardly, hardly
D．hardly, hard
