21.The sign says"No smoking".You...................smoke
a.can
b.are not
c.must not
d.must
22...................do the buses run?-Every twenty minutes
a.how far
b.what time
c.how often
d.how much
23.Mary and I are looking forward....................you
a.of seeing
b.for seeing
c.to seeing
d.to se
24.If you work long hours,you....................exhausted
a.will be
b.would be
c.would have been
d.will
25.The manager told me ........................harder
a.work
b.to work
c.worked
d.working
26.The coffee is........................hot than I can't drink it
a.too
b.very
c.such
d.so
27.His father told......................stay up late
a.to not
b.him not to
c.not to
d.him to not
28.Coins last approximately twenty times....................paper notes
a.longer
b.as long
c.more longer
d.longer than
29.I want a....................of orange juice
a.slice
b.bar
c.piece
d.carton
30.Be careful when you.......................the oil into the flying pan
a.serve
b.pour
c.beat
d.fold