The tiger, once a ____ animal to humans, is now ____of disappearing on the earth.
It is reported that the United States uses ______ energy as the whole of Europe.
I thought him nice and honest ______ I met her.
It is not who is right but what is right ______ is of importance.
I wonder how he could ______ not handing in his math exercises yesterday, for his math teacher is always strict with his students.
We are looking forward to ______ the problem of the traffic accident ______.