She tried to stay calm on the stage, but her trembling voice _______ her                                      nervousness.

A．gave away

B．gave up;

C．gave off

D．gave out

( )是指由两种或者两种以上利益相结合而产生的价值附加增值，其中，组合利益的价值要大于原有各项利益价值的加和。

A．在用价值
B．保险价值
C．协同价值
D．升值价值