With the word “PM2. 5” constantly __________ in media reports, you might be wondering what on earth it means.
There was ______ time ______ I hated to go to school.
Please _______ the numbers and I’m sure they will ______ more than 1,000.
What I need is ___________ book that contains __________ ABC of oil painting.
---What’s your comment on the match? --- We ________, but today was not our day.
The experts have given some practical advice ______ the problems that most people are concerned about in food safety.