Many scientists say that it’s important for us to have ______ food in our diet.
--Excuse me, teacher, can I ask you something about the last class? I didn’t quite understand it. --Sure! Please feel _________to ask me anything!
--Excuse me, can I have this seat, please? --I’m sorry, but it’s_______.
—You see, China is becoming stronger and stronger now. —Yes. That’s why Chinese _____ in more and more schools out of our country.
The two brothers didn’t quite get along well _______the past, but now they are like peas and carrots.
______ English is ______ useful language.