"But the main cause of the economic problem is political in nature."

Then he got into what was wrong with the world and the main causes of it.

There are two views on the main cause of the problem.

The main cause of her death is still in question.

A sharp fall in drug production was the main cause.

This was later considered to be the main cause of the disaster.

He's the main cause of our not having talked before now.

This results in the main cause of time loss within the game.

It is the main cause of death in the under-50s age group.

That is a main cause of worry for the press.