本币和外币进行货币互换，外币支付方互换价值为外币债券价值减去本币债券价值。
参考答案：错
At the foot of the hill you could hear nothing but the _____ of the running water.
A． shout
B．noise
C．voice
D．sound
滑轮又名滑子，分为______、______、______。
