Fortunately, the hospital’s new air- conditioning system ______ when the first heat wave of the summer arrived.
A.had been installed
B.had installed
C.installed
D.had been installing

The City Parks Department is putting in several miles of new trails because so many people have said that they enjoy ______ on them.
A.to walk
B.being walked
C.walking
D.to be walked

You’d better save some money for a rainy day. You can’t count on ______ by your parents every time you get into financial difficulty.
A.being rescued
B.rescuing
C.to rescue
D.to be rescued

The man died because medical help was not summoned. A doctor should _______ immediately.
A.be called
B.have been called
C.have called
D.called

Richard really didn’t mind_________ by the party to celebrate his fortieth birthday although he told his friends that they shouldn’t have done it.
A.to be surprised
B.being surprised
C.surprising
D.to surprise

Ann hoped _______ to join the private club. She could make important business contacts there.
A.to be invited
B.being invited
C.inviting
D.to invite

Are you sure you told me? I don’t recall______ about it.
A.having told
B.to have been told
C.having been told
D.to have told

David appears ______ some weight. Has he been ill?
A.to have lost
B.having lost
C.having been lost
D.to have been lost

Tom made a serious mistake at work, but his boss didn’t fire him. He‘s lucky ______ a second chance.
A.to have given
B.having been given
C.having given
D.to have been given

Dr. Nguyen is a brilliant and dedicated scientist who had expected to be selected as the director of the institute. She was very surprised not _______ the position.
A.having been offered
B.to have been offered
C.having offered
D.to have offered