A.saw
B.watched
C.noticed
D.observed

A.be fit for
B.make good use of
C.play a part of
D.take the place of

A.since
B.for
C.during
D.in

A.a sick
B.an ill
C.sick
D.ill

A.trip
B.travel
C.tour
D.voyage

A.took off
B.put off
C.flew off
D.left off

A.is
B.are
C.am
D.be

A.writing
B.to write
C.having wrote
D.to have written

A.raise
B.keep
C.grow
D.take

A.but to think
B.thinking
C.to 
D.think

A.being worthy of
B.worthy of
C.which worth
D.which worthy of