It`s difficult ___ your sound because the moise is too high.

It`s difficult ___ your sound because the moise is too high.A.to listen B.to know C.to learn
It`s difficult ___ your sound because the moise is too high.
A.to listen B.to know C.to learn D.to hear
为什么不选BC我知道原因,至于为什么不选 to listen是不是改成to listen to就可以了?
另外想再请教一下如何区分 alone 和 lonely