China has a growing number of middle-class parents who _____ for years to get their only child into a top school．

A．had been saved

B．have saved

C．had saved

D．have been saved

解决投资争端国际中心在解决投资争端时，应适用( )。

A．东道国法律(不包括冲突规范)

B．双方同意的法律规则

C．东道国法律或国际法原则

D．国际惯例