The professor asked a question, and David ________ a good answer.

He would have given you more help, if he ________ so busy.

After months of voyage, Columbus arrived in ______ later proved to be a new continent.

It rained hard yesterday, ______ prevented me from going to the park.

It is important to ________ your skin from the harmful strong sunlight.

He was ______ to withdraw from running for the presidency.

The two girls competed with each other ______ the highest mark.

If the operation ________ carefully prepared, it would not have been successful.

It took me a month to get rid _______ the cough.

The furniture in her bedroom is quite different from ________ in the living room.