serious problem
Думаю, это серьёзная проблема.
I think this is a serious problem.
This is a serious problem.
Is this a very serious problem?
We have a serious problem.
This is a very serious problem.
Злоупотребление алкоголем среди молодёжи-серьёзная проблема.
Alcohol abuse among young people is a serious problem.