Although the police thought he was the most likely one, _____ they had no exact proof about it, they could not arrest him.
With the word “PM2.5” _________ appearing in media reports, people pay greater attention to it and seek health tips for smoggy days.
Tom’s pay depends on ______ the factory.
A good teacher is ______ who teaches not only with mind but also with heart.
---What do you think of my homework? ---Good work,________ a few slight mistakes.
People all over the world have a dream ______they will always live a peaceful life.