I didn’t hear （ ） because there was too much noise where I was sitting.

These three teachers vary_____their manners of teaching.

The manager urged his staff not to （ ） the precious opportunity.

Today, household chores have been made much easier by electrical （ ）.

Tom might not have made such a serious mistake if he _____ your advice.

—Do you like the material? —Yes, it （ ） very soft.

The whole class couldn’t help _____ when they saw the haircut of their new classmate.

Only when you have obtained sufficient data （ ） come to sound conclusion.

I don’t like to _____ a room with a stranger.

Our daughter didn’t know what to （ ） when she first entered the university, as she hadn’t make up her mind about her future.

These tickets for the performance are （ ） until the end of the month．

A new technique （ ）, the output as a whole increased by 20 percent.