With the word “ PM2.5” ________ appearing in media reports, people pay greater attention to it and seek health tips for smoggy days.

It was a real race________time to get the project done.Luckily，we made it.(2013·新课标全国Ⅰ，34)

— David hasn’t come yet.—I think he will ______ soon, for he means what he says.

It is believed that the tight employment market has forced job seekers to_______whatever work is available.

In manufacturing, cheaper materials are constantly being        for the better, more expensive kind.