方钻杆上下旋塞及开关工具的保管、操作由（）负责。
A.外钳工
B.内钳工
C.架工
D.场地工
参考答案：A
填空。
1. I think the _______(第十二)lesson is the most difficult of all .
2. Jim is so careless that he always _______(犯错误).
3. She want _______(参加) the party tonight.
4. With the development of _______(社会), more and more people buy cars.
5. Our _______(友谊) will be remembered forever.
骨肉瘤的X线片改变
A．日光放射现象B．葱皮样骨膜反应C．大量棉絮样肿瘤骨D．膨胀性皂泡样改变E．膨胀性磨砂样改变
