吊挂水棚的挂钩，应采用直径（）毫米的圆钢。
A、2－6
B、2－8
C、4－8
D、4－10
参考答案：C
中耳包括____、____和____。
--- How is everything going on with you in Europe?
--- Quite well, not so smoothly as I hoped, ____.
A．though
B．instead
C．either
D．too
