He glanced around the room.

他环视了一下房间。

She glanced around; found herself alone, and the next instant she had the book in her hands.

她扫视四周，发现自己孤身一人，下一瞬间她手里就拿着那本书。

I glanced around the room before I left.

我离开房间以前扫视了一下四周。

I glanced around the room before I left.

我略略环视了一下房间才离开。

The headmaster glanced around our classroom.

校长环视了一下我们的教室。