将下图(a)改为(b)是为了防止螺栓连接的（）
A.栓杆被剪坏
B.杆与孔的挤压破坏
C.被连构件端部被剪坏
D.杆受弯破坏
参考答案：A
—It’ s getting dark. Has Mr. Johnson finished his house?
—I have no idea,but this morning he was painting it.
A．to paint
B．painting
C．having painted
D．to have painted
下列不属于苦味药作用的是（）。
A.行气
B.通泄
C.燥湿
D.降泄
E.清泄
