PART II    PROOFREADING & ERROR CORRECTION (15 MIN.)

Directions: The following passage contains ten errors .Each line contains a maximum of one error. In each case only one word is involved. You should proofread the passage and correct it in the following way:

For a wrong word, underline the wrong word and write the correct one in the blank provided at the end of the line.

For a missing word, mark the position of the missing word with a "^" sign and write the word you believe to be missing in the blank provided at the end    of the line.

For an unnecessary word, cross the unnecessary word with a slash "/" and put the word in the blank provided at the end of the line.

EXAMPLE
When ^ art museum wants a new exhibit,
(1) an
it (never/) buys things in finished form and hangs
(2) never
them on the wall. When a natural history museum   
wants an exhibition, it must often build it.
(3)exhibit

[A]

One important outcome of the work on the expression
of genes in developing embryos is sure to be knowledge
that can help preventing birth defects. Just as promising
(1)
is the possibility of unraveling the complicated wiring
(2)
of the brain. A mechanic gets valuable insight how an
(3)
automobile works by rebuilding car engines; similarly,
neuroscientist can learn how the brain functions from
(4)
the way it is put together. The next step pursuing the
(5)
goal is to find out how the blueprint genes, the homeobox
genes, control the expression of other genes that create the
valves and pistons of the working cerebral engine. The
protein encoded by the later genes could change the
(6)
stickiness of the cell surface, the shape of the cell or its
metabolism to create the characteristics peculiar to, say,
neurons or neural-crest cells. Surface proteins may be the
mechanism, whereby similar programmed cells stick

(7)
together to form specific structures; they might also sense
the local environment to help the cell decide what is to do.
(8)
Clarifying those mechanisms will engage the best talents in
embryology and molecular biology for some times to come.
(9)
What is perhaps the most intriguing question of all is if the
(10)
brain is powerful enough to solve the puzzle of its own creation.