The relationship of 'hurricane alley' to climate change is a difficult topic.

The seminal study in a Western language on a difficult topic.

You are entering a difficult topic on the "nature" of physical science.

I mean fun in the sense that we get to really understand, as usual on this program, a very deep and a difficult topic.

Now in her nineties, she has written about the difficult topics of old age and dying.

Both of the books are around 115 pages and adequately handle their difficult topics.

On the very difficult topic of opening up the national networks, your House has proposed a new compromise.

"It is a difficult topic to research because you must read a lot of ancient texts," he said.

The better your English language skills, the more you are able to talk about difficult topics.

The treatment of the mentally ill by the criminal justice system has long been a difficult topic.