—How much is _____ for a schoolbag?— Experts say students should carry _____ more than 10% of their body weight.
By improving reading skills, you can read faster and understand more of ______ you read.
----That is ________ you spent your summer holiday, isn’t it?---- That’s right.
Human beings are different from animals _________ they have languages.
At school, some students are active, ______ some are shy, yet they can be good friends with one another.
___________ seems hard to believe is that the bird the officer uses is the same bird often seen in public parks----the pigeons.