The most important thing of all is for you to be extremely careful.

And if I'm not extremely careful, it might be the last.

It was suddenly very important to know if they had met, but he would have to be extremely careful.

Still, the house was far from deserted, and the figure had to be extremely careful.

A. Yes, and we have to be extremely careful about that.

"The natural thing to do is to be extremely careful," he said.

He was extremely careful these days about his behavior, which left no room for criticism.

"We should be extremely careful not to give him something he doesn't have."

What harm could be done, if she were extremely careful?

"Then I shall have to be extremely careful to return to you in one piece."