School children must be taught how to deal with dangerous .
It is ________ that Arthur gave back the money he found.
They have ______ a plan for reducing the budget deficit(财政赤字), which is quite practical.
I waved to Nancy, but she was _______ in her thought, and made no response.
With ______ help of his teachers, he made ______ great progress in his study.
I _____ in the street when someone _____ me.