16.He always leaves _______ for all the words he does not know in his translation.
A.blankets B.blind C.black D.blanks
17.Smoking and drinking are regarded as _______ in some countries because they do no good to health.
A.vices B.habits C.customs D.copies
18.The news has not yet been officially _______ by the government.
A.struck B.confirmed C.founded D.pointed
19.These are two _______ issures, but people often take them as one.
A.ruin B.nest C.distinct D.castle
20.What _______ did you watch on television last night?
A.wave B.frequency C.channel D.tunnel
16.D 17.A 18.B 19.C 20.C