Although the causes of cancer_____, we do not yet have any practical way to prevent it.
A.are being uncovered B.have been uncovering
C.are uncovering D.have uncovered
With just four years _______, the Brazil Olympic organizers have promised to deliver an equally inspirational ceremony.
A.gone B.to go C.going D.go
We are so sorry for that.We'll try to determine exactly _________ went wrong that evening.
A.where B.what C.which D.how
If you go there by ____train ,you can have quite a comfortable journey ,but make sure you get ___fast one.
A./; / B./; a C.the; a D.the ; /
Visitors were _____at the _____pictures that the guide showed.
A.amazed; amazing B.amazed; amazed
C.amazing; amazing D.amazing; amazed
— I think my child’s behavior is _______ .
— No, he just has a lot of energy.
A.information B.natural C.normal D.abnormal