Everything he _____ to his country. [ ]

The scientists are looking ______ the problem with air pollution in the city[ ]

–I don’t feel like going out. Why don’t we just stayhome and watch TV instead — ____ You promised to take me out fordinner and to the theatre on my birthday.

. —Do you often attend meetings — Yes, I ________ organizational meetingsat the end of every month..

The students went into the classroom,________.