无效劳动合同自( )起，就不具备法律效力。

A．履行劳动合同之日

B．订立的时候

C．确认劳动合同无效之

D．发现劳动合同无效之日

The would-be taxi drivers have to        a very tough training period to get their licenses.   [ ]

A. go through

B. get through

C. pass through

D. put through