16.The thief was _______ by the police at the railway station.
A.carpet B.mined C.captured D.mounted
17.In fact, there is no _______ liberty in any country.
A.adequate B.absolute C.private D.practical
18.There is too much noise outside. I can not _______my attention on my work.
A.connect B.flat C.fill D.concentrate
19.While studying at U.C.L.A.,Mr.Wang _______ his old friend, whom he has not seen for nearly twenty years.
A.encountered B.whispered C.swung D.maid
20.The _______ production of engines in our factory has doubled this year.
A.manual B.annual C.amount D.alike
16.C 17.B 18.D 19.A 20.B