()的主要作用是定压溢流和过载保护。
A.分流阀
B.节流阀
C.溢流阀
D.调速阀
参考答案:C
利率期货主要以各类()金融工具作为基础资产。
A.浮动利率
B.官方利率
C.市场利率
D.固定收益
________in Paris for five years, but still can't read and write in French.[ ]
A. Having lived
B. Having been living
C. He has lived
D. Although he has lived