98.As far as I know, no such drugs are ever known to work.

四级词汇讲解:
口语中经常以as far as I know作为一句话的开头，意为“据我所知”，其后的内容便是说话的重点，这也正是听力的常见设题点。no such…ever…意为“此类……从未……”，表示强调。句中的work意为“有效果，起作用”。

英语四级考点归纳：
听力中与as far as I know类似的表达还有:

※ as/so far as I'm concerned意为“就我而言”。如:
So far as I'm concerned, I"m not going to run the program。就我而言，我不会去运 作这个项目。

※ as far as sb./sth. is concerned意为“就某人或某事物而言”。如:
As far as performance is concerned, we've done quite well.就表现而言，我们做得还不错。

※ as far as it goes意为“就其本身而言”。如:
The statement is correct as far as it goes.该表述就其本身而言是正确的。