要实现快速运动可采用以下哪种回路？（）
A.差动连接
B.调速阀调速
C.容积调速
D.容积节流调速
参考答案：B
什么数的60%是15？
If a Chinese pats lightly his own stomach by one or both open hands after a meal, he means "()".
A. I’m full
B. I’m hungry
C. Come here
D. Thank you
