用括号中所给词的适当形式填空。Many animals may _______ (appear) one day if we don't protect them well.
If the number of one kind animal drop too low, it will bring _______ (dangerous) to the whole ecosystem.
______ (recycle) paper is very easy.
Mr. Green rides a bike to work instead of _______(drive) his car now.
While you ______ (wash) your face, you'd better turn off the lap.