I came here          to see you.

The incomes of skilled workers went up.________，unskilled workers saw their earnings fall.

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

The charity sale our school organizes every year has taught us much. _______ we would never have learned it in class.

Nowadays, a lot of children have less time to play and communicate with their peer due to extra studies. ________, it is difficult to develop their character and social skills.