20．-Why do you look so upset?

　　　 -There are so many troublesome problems ____________．

　　　 A．remaining to settle 　　　　　　　　　　　　　　　 B．remained settled

　　　 C．remaining to be settled　　　　　　　　　　　　　 D．remained to be settled

19．The driver managed not to hit the child who ran in front of his car, but only ____ injuring himself．

　　　 A．in hopes of 　　　　 B．as a consequence of

　　　 C．at the mercy of 　 D．at the cost of

18．The new tax would force companies to ____ energy-saving measures,

　　　 A．adopt　　　　　　　　　 B．adjust　　　　　　　　　 C．adapt　　　　　　　　　 D．accept

17．Please ____ my suitcase while I go to buy my ticket．

　　　 A．have an eye for 　 B．keep an eye on　　 C．take care for　　　　 D．be careful on