Great attention must be paid ____ welfare, especially in the poor area. [ ]

How much do you know about the 3D film technology?— A little. Not until _____ the hot movie

There is no doubt _____ he will finish thetask in time.

ep up with their work, the vast majority of office clerks today must read letters, reports, trade publications, interoffice communications, to say _______ of newspapers and magazines.

The students were sitting in the classroom with their eyes on the teachers.