This action by the high command is a serious development.

This is a very serious development for the entire world.

No nation is known to have done any serious development of this type of weapon.

He thought the Syrian sweep was a serious development but not a catastrophic one.

"But this is an extremely serious development, and it may have bearing on what you decide."

There was another more serious development: the dramatic change in the structure of taxation.

From 1950 serious development in the fishing industry had begun to take place.

The deal ended due to lack of funds to start serious development on the project.

"It's a very serious, shocking development, and we're still considering how to deal with this."

We began our work long before these recent, serious developments, which are covered in another piece of work.