我国股票市场上目前绝大部分是普通股票。 ( )
参考答案：错
It was difficult to tell exactly _______ the saying began, but it is possible that it was in the theatre or movie industry.
A．where
B．when
C．why
D．that
草原的优势植物以( )为主。
A．禾本科B．豆科C．莎草科D．菊科
