He didn't _____ what I read because his mind was on something else.
There was a________ look on his face when he met with the________ problem.
You’d better go there by train. The train ticket is________ the airplane ticket.
—Shall I give you a ride as you live so far away? —Thank you,________.
At times the balance in nature is____, resulting in a number of possibly unforeseen effects.
If I ruled the world,I would________ the world________ everything that is bad.