If energy………inexpensive and unlimited, many things in the world would be different.
A.would be
B.will be
C.is
D.were

____________ I a billionaire, I would travel around the world.
A.
B.Was
C.Were
D.Do

___________ my mother to stay at home now, she would cook a lot of delicious food.
A.
B.Does
C.Were
D.Had

___________ you gone to the cinema with me yesterday, you would have been satisfied with the film.
A.
B.Have
C.Had
D.

If you ……… to my advice in the first place, you wouldn’t be in this mess right now.
A.listened
B.listen
C.had listened
D.will listen

………….. interested in that subject, I would try to learn more about it.
A.
B.I was
C.Were I
D.Should I

If I ……… the same problems you had as a child, I might not have succeeded in life as well as you have.
A.had had
B.should have
C.would have
D.have

I…………you sooner had someone told me you were in hospital.
A.visit
B.visited
C.had visited
D.would have visited

……….more help, I could call my neighbor.
A.I should need
B.I have needed
C.Should I need
D.Needed

……….. then what I know today, I would have saved myself a lot of time and trouble over the years.
A.If I would know
B.If I know
C.Had I known
D.Did I know