I just wonder ________ that makes him so excited.
—I am sorry I didn’t do a good job.—Never mind.________, you have tried your best
Full use should be _______the natural resources to combat the energy crisis.
Our classroom is very clean. Do you know who__cleaned it﹖
The great hall was crowded with many people, _____ many children _____on their parents’ laps.
________ of my sisters are experts in agriculture. Helping the farmers improve their farming techniques _________their duty.