填空题 The passage contains 10 errors. Each indicated 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 {{U}}wrong{{/U}} word, underline the wrong word and write the correct one in the blank provided at the end of the line.
For a {{U}}missing{{/U}} 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 {{U}}unnecessary{{/U}} word, cross the unnecessary work with a slash "—" and put the word in the blank provided at the end of the line.
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 unravel 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.