By the time she was done the room full of cages had become almost dark.

It had become very dark, although I knew that dawn must be near.

Curiously the darkness seemed to have become more dark.

It had become dark and cold; I should have brought a cloak.

He clung to that illusion, even after he opened his eyes again, for the room had become quite dark.

Now, with baffling suddenness, the room had become totally dark.

Over the black bush of beard his eyes had become dark and hollow.

But it was becoming too dark to see.

Everything was becoming strangely dark, as if a film was forming over his eyes.

The ware at this temperature became dark brown and vitreous.