The impact of acid rain on American forests has been a contentious subject.

It would preserve the peace, while remaining silent on all contentious subjects.

This has been a contentious subject in computer science.

How to honor our nation's heroes is always a contentious subject.

John Sessions (above) will open the afternoon with a specially written piece on this contentious subject.

Inflation had become a particularly serious and contentious subject.

In modern times, the masks have been a contentious subject among the Iroquois.

Of course Katie thought he was the right age and she had been stupid to bring up such a contentious subject.

Tank losses in the battle have been a contentious subject.

This is a very interesting article on what's likely to become quite a contentious subject.