I feel that geometry is a difficult subject.

我认为几何是一门难学的课程。

youdao

It can be a difficult subject to talk about.

这可能是个难以启齿的话题。

youdao

Though physics is a difficult subject, we like it.

尽管物理是一个难学的科目，但我们都喜欢它。

youdao

Describing the clashes between Christians and Muslims in the south, she treats a difficult subject with intelligence and sensitivity.

CNN: Two women on an intriguing stroll through Asia

But it is a difficult subject for Egypt, which has no fondness for Hamas, the Palestinian off-shoot of Egypt's banned Muslim Brotherhood.

NPR: Rice Plans More Prep Work for Mideast Talks

Autopsy, like organ donation, is a difficult subject to broach with grieving families (though the public good associated with both can help the grieving process).

ECONOMIST: Autopsies