With the word “PM2. 5” constantly __________ in media reports, you might be wondering what on earth it means.
.________beat Xiao Ming black and blue is not known.
_______ I can see, there is only one possible way to keep away from the danger.
He is a ________child and his parents are ___________ with him.
These rivers should be prevented ___________.
He found himself _________ in a hospital bed.