6个人分乘两辆不同的汽车,每辆车最少坐2人,则不同的乘车方法数为[ ]
A.40
B.50
C.60
D.70
答案:B
—Would you like to come for supper?
—______.[ ]
A. I'd love
B. I'd love to
C. No, I can't
D. No, I wouldn't
带式输送机上自动调心托辊的工作原理是什么?