内痔的主要症状是（）。
A.便血，疼痛
B.便血，有分泌物
C.便血，脱出
D.便血，肛门痒
E.便血，异物感
参考答案：C
— Hi, Terry, can I use your computer for a while this afternoon?
— Sorry. _____. [ ]
A. It's repaired
B. It has been repaired
C. It's being repaired
D. It had been repaired
(一)题6-1～题6-3，分析螺纹画法中的错误，并在下面指定位置绘制正确的两视图。
