Which do you enjoy ____ your spare time, surfing the Internet or building up your strength?

Bell is considered _____ the first phone in 1896.

There was a _____ look on his face. He found what the expert said too difficult to understand.

When he looked up, he suddenly found himself          by a group of teenagers,

Victor apologized for　　　　　　  to inform me of the change in the plan.

It seems you need to apologize quickly ______ a good friend.

________comfortably in his chair, the old man enjoyed music with his eyes half_________.

________by the advances in technology, many farmers have set up wind farms on their land.

Simon made a big bamboo box       the little sick bird till it could fly．

____ to Anne's birthday party. Mr. Brown is now searching shop after shop for a nice present for her,