在分级变速主传动系的设计中，基本组的级比指数为（）。
A、1
B、2
C、3
D、4
参考答案：A
空调压缩机电磁离合器的作用是（）压缩机的工作。
What is suggested for your investment().
A.Distributing your money among different companies.
B.Investigating the company before investment.
C.Don’t invest all your money.
D.Comparing different companies before investment.
