Prior to 1990, the Act had proved completely ineffective in dealing with acid rain.

1990年以前，该法案在处理酸雨问题上毫无建树。

youdao

Prior to 1990, the Act had proved completely ineffective in dealing with acid rain.

1990年以前，该法案在处理酸雨问题上毫无建树。

youdao