楼下翻译得不全。 by no means clear = certainly not clear 不确定
It is certainly not clear what the president can do to end the strike.
尚不确定总统能采取何种方式结束此次罢工。
that与what都可引导
主语从句,that在从句中不作
句子成分,但不能省略。
what 在从句中可作主语、宾语、
表语等,不能省略。
这里what作从句里的宾语“ the president can do [what] to end the strike."
如果这句的从句部分有自己的宾语,例如,
the president can do [anything] to end the strike
那这里就需要用that引导,
It is by no means clear that the president can do anything to end the strike.