The vaccine generated by reverse genetics is required to review in that ______.
A. it has strong side effect to the elderly.
B. it may turn ineffective in a short period.
C. it is useless in preventing the virus.
D. it hasn't been tested in humans.
What is the author's attitude towards the newly developed bird flu vaccine？
A. Slightly approves of.
B. Depicts neutrally.
C. Slightly disapproves of.
D. Completely rejects.
It can be inferred from the last paragraph that ______.
A. Washington's intellectual and cultural life is unbalanced.
B. there is social division between intellectuals and black locals.
C. the cultural revival brings jobs and vitality to the downtown.
D. Washington solves its own problems before fixing the world.
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