阅读理解。
Most scientists agreed that cloning an entire human being-besides morally
questionable-was filled with technical problems. After all, research into animal cloning
has already shown that there are hundreds of failures, includingmanybadlydeformed
(畸形的)creatures that were usually miscarried.
Now comes word that it might be easier to clone humans than was previously
believed. People have a genetic quirk(怪癖) that might prevent some of the
developmental deformities associated with animal cloning. One gene, called IGF2R,
is normally imprinted in sheep, cows and mice but not in humans. Human clones would
always inherit non-imprinted IGF2R genes, so there would be no chance of a mix-up
and, their growth would be normal. But what of the other 49 0r so imprinted genes
(遗传基因 ) ?No one knows what troublethey might cause. So the fact humans have
one less imprinted gene than mice, sheep or cows means that human
cloningmightbemarginally (轻微地 ,很少地 ) easier , but not necessarily safer.
1. At present, scientists' opinion about cloning human is that_____
A. it will bring out many developmental deformities
B. it faces no moral problems now
C. it might be easier but still not safer
D. it is proved by practice that it is easier, only not so safe
2. What caused many badly deformed creatures in animal cloning?______
A. A gene called IGF2R.
B. A genetic quirk.
C. A non-imprinted IGF2R.
D. Not clearly found.
3. How many imprinted genes might bring danger to human cloning?______
A. 51.
B. 50.
C. 49.
D. 48.
4. The writer didn't say but we can infer that his attitude towards cloning human is that______
A. it should be encouraged
B. it should be properly controlled
C. it should be stopped
D. it should be forbidden by law
