系统性硬化症的病理特点是
A.中、小动静脉血管炎
B.滑膜炎
C.肌炎
D.胶原增殖、纤维化
E.肌腱端炎
参考答案:D
In the reading room, we found her seated at a desk, her attention ____ on a novel.
A.fixing
B.to fix
C.fixed
D.having fixed
分配电箱与开关箱的距离一般不超过( )m。
A.10
B.15
C.20
D.30