Parents are under a(n) to educate their children.
A. responsibility B. duty
C. liability D. obligation
Sorry, I’m late. I ______ have turned off the alarm clock and gone back to sleep again.
A. might B. should
C. can’t D. will
We _____ for her because she never came.
A. mustn’t have waited B. shouldn’t have waited
C. mustn’t wait D. needn’t wait
Meeting my uncle after all these years was an unforgettable moment, _______ I will always treasure.
A. that B. one
C. it D. what
The cause he had devoted himself ______ a perfect success.
A. to proved B. proved
C. to prove D. to proving
It is generally believed that teaching is _______ it is a science.
A. an art much as B. much an art as
C. as an art much as D. as much an art as
