9 Penicillin was discovered by chance in 1928.
A finally
B accidentally
C experimentally
D opportunely
10 Bladder wrack， a tough， leathery brown seaweed， clings to rocks tenaciously.
A grows under
B hides under
C sticks to
D yields to
11 Sue was distraught waiting for her mother to come to last night.
A make a social debut
B regain consciousness
C come home in spite of difficulty
D meet her immediately
12 Psychologists have done extensive studies of how well patients comply with doctors orders.
A obey
B understand
C improve with
D agree with
13 The Taconic Mountains form part of the dividing line between New York and Massachusetts.
A geographic dispute
B boundary
C scenic attractions
D territory
14 My wife wants me to do away with my shoes.
A dispense with
B get rid of
C do without
D maul
15 The Pop Art of the 1960s used imagery drawn from the everyday world.
A understood by
B approved by
C censored in
D taken from