扳桩是用（）、（）制成，使用时插入地中用以承受较小压力，按受力要求，有单桩、多桩之分。
参考答案：圆钢；角钢
— Tom is planning to buy a car.
— I know. By next month, he enough for a used one.
A．saved
B．has saved
C．would save
D．will have saved
对于牙源性上颌窦炎，拟拍片位是
A．全口曲面断层片及华氏位片
B．根尖片及全口曲面断层片
C．根尖片及华氏位片
D．华氏位片及上颌体腔片
E．根尖片与上颌体腔片
