骨关节结核早期X线片表现（）
A.骨空洞形成
B.层状骨膜增生
C.边缘不齐的小死骨
D.骨质缺损
E.骨小梁模糊，呈磨砂玻璃状
参考答案：E
—Allan looks tired out.
—Sure. He in the gym for two hours.
A．works out
B．had worked out
C．has been working out
D．was working out
如何延长柱塞泵填料的使用寿命？
