---You are sweating. ______ I fetch you some water?  ---It’s so kind of you. 

—I ________ speak English in class because I’m afraid of making mistakes. —Don’t be shy. Believe in yourself and everything will be OK. 

When we worked in the same office，we _______ often have coffee together.

One of the National Health Regulations is that public schools ______ actively create conditions for sports facilities opened to the public.

--- Listen! David is talking happily with his mother in the next room.　--- It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.