加工台阶轴时，主偏角应（）90°
A.小于
B.大于
C.等于或大于
D.等于
参考答案：C
The young graduate ______ his vegetable farm so successfully that soon he became No 1 vegetable
producer in the area. [ ]
A. made
B. performed
C. worked
D. discovered
对于地基承载力较低、台身较高、跨径较大的梁桥，应优先选用的桥台形式是( )。
A．轻型桥台 B．框架式桥台C．重力式桥台 D．柱式桥台
