_____ we were worried about was _______ they could manage to control the pollution.
We are at your service. Don’t ________ to turn to us if you have any further problems.
Tom, turn down the music. Why ________ you make such a big noise while your baby sister is sleeping?
It rained for two weeks, completely ________ our holiday.
I don’t think it is teachers who ________ for giving students too much pressure.
Much new high technology has been introduced from America, ________ a great increase in the production of the company.