When I was walking in the street, I saw a plane___________ over my head.

The boy was so ______ in reading that he didn’t hear his father knocking at the door.

. From this simple concept ________ that has caused a great change in farming.

Whathonest boy! And he isbest student of all.

The temperature now is much higher than______of 100 years ago because of more and more greenhouse gas.