The old couple have been married for 50 years.No wonder they_____each other so much!

The old couple have been married for 50 years.No wonder they_____each other so much!
A.know B.had known C.knew D.will know
We climbed up to the top of the mountain,from ____we had a good view of the whole city.
A.principle B.situation C.attitude D.character
Books borrowde from the city library_____be returned in two weeks' time.
A.would B.may C.could D.shall
John sold most of his things.He has hardly____left in the house.
A.nothing B.anything
——I failed to pass the driving test again.
——______!It's not that bad.
A.cheer up B.It doesn't matter