某调制解调器同时使用幅移键控和相移键控，采用0、π／2、π和3／2π种相位，每种相位又都有2个不同的幅值，在波特率为1200的情况下数据速率是()。
A. 7200bps
B. 4800bps
C. 2400bps
D. 1 200bps
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We may infer from the first paragraph that______.
A. the amount of freedom to be enjoyed by the citizens of a given country is inversely proportional to the degree of sustained economic prosperity
B. the amount of freedom to be enjoyed by the citizens of a given country is dependent upon the degree of sustained economic prosperity
C. the impact of institutional effectiveness on economic development is being underrated
D. a free society in which governmental agencies and organizations have achieved the highest level of development and efficiency is yet to be invented
As mainstream chip production technology shifts from one generation to the next every three to five years, plants with new technology can make more powerful chips at lower costs, ______plants with outdated equipment, which often cost billions of dollars to build, will be marginalized by the maker.
A. because
B. even though
C. while
D. since
The writer's experiment shows that downshifting______.
A. enables her to realize her dream
B. helps her mold a new philosophy of life
C. prompts her to abandon her high social status
D. leads her to accept the doctrine of She magazine
Comics as in the last but third paragraph means______.
A. comedy
B. funny stories
C. cartoons
D. beautiful stories
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