皮带轮裂损或因磨耗至使新皮带与槽底面间隙小于（）时更换。
A.1mm
B.2mm
C.无间隙
D.3mm
参考答案：D
The fact of Madam Curuie’s_______ to the radiation for a long time ______ her poor health.
A．being exposed;contributed to
B．exposed ;led to
C．having exposed;resulted in
D．exposing; resulted in
滑膜肉瘤的特点是（）
A.关节面破坏明显
B.常绕肌腱生长
C.好发于骨干边缘
D.好发于儿童
E.钙化多见
