The phrase "ward off' in the fourth paragraph is closest in meaning to
A. cure.
B. keep away.
C. worsen.
D. relieve.
From the passage, we learn that the author
A. feels it necessary to take vitamin pills.
B. thinks pill-takers are healthier than those who don't.
C. suggests high doses of vitamins may result in heart disease.
D. finds out an unsatisfied conclusion about taking multivitamins.
数据-1，0，3，5，x的方差是34/5，则x=()．
A. -2或5．5
B. 2或5．5
C. 4或11
D. -4或-11
E. 3或10
The author thinks what has been found about fashions by the scientists and the historians
A. incredible.
B. amazing.
C. reasonable.
D. creative.
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