Matt told you about his part-time job at a convenience store. One day, a
suspicious-__21__ customer came into the store. Matt suspected that the guy had sticky
fingers. He watched him carefully and caught him red-handed trying to slip a packet of
gum into his pocket.
    You might have a difficult time __22_ what Matt was talking about. However, from
the context of what he said and the way __23____ he used the words, you could figure out
that Matt wanted very much to buy a really expensive cell phone, and __24____ he had to
work very hard to make enough money to buy it. In the store, Matt saw a shoplifter who
was trying to steal some gum, and he caught him on the spot.
    Idioms may be difficult to understand, and may take a lot of time to learn. However,
they make our language __25__ more interesting and colorful. Learn more about them,
and you will find that using and understanding them can be a lot of fun!
【題組】21.
(A) looks
(B) looked
(C) looking
(D) looked at