把物体拉上斜面，斜面（）则省力。
A.长
B.短
C.坡度大
D.坡度小
参考答案：D
常用的蝶阀有（）。
A．对称式蝶阀
B．对夹式蝶阀
C．移动式蝶阀
D．法兰式蝶阀
She is honest and trustworthy. I think It's ______no business of hers.
A．absolutely
B．possibly
C．unfortunately
D．desparately
