Why the sudden interest in a car that is almost 30 years old?

"Why this sudden interest in what I do with my life?"

He couldn't understand this sudden interest the girls were taking in me.

How do we know what is at the bottom of his sudden interest in you?

He stopped well short of the chair and developed a sudden interest in the view out the window.

"Why have you taken such a sudden interest in this trial?"

The sudden interest is a marked change from a few months ago.

I asked with sudden interest, turning slowly to look at him.

Why this sudden interest in an event that took place nearly 70 years ago?