David, ________ you show me the way to use this machine?
A.could B.may C.should D.must
The society is developing fast. We________ keep learning to catch up with the development.
A.might B.had better C.could D.may
________we invite Jim and his sister to our game? They are also our friends.
A.Must B.Shall C.Would D.Need
Students ________ read more books because they can help them be better people.
A.must B.can C.may D.should
Have a glass of water, please. You ________ be thirsty after a long walk.
A.should B.must C.need D.could
Necessary action ________ be taken to protect the environment so that we can have a better world.
A.can B.must C.may D.would