某同学使用计算器求30个数据的平均数时,错将其中一个数据105输人为15,那么由此求出的平均数与实际平均数的差是[ ]
A.3.5
B.-3
C.3
D.-0.5
答案:B
Leonardo da Vinci(1452 - 1519) birds kept in cages in order to have the pleasure of setting them
free. [ ]
A. is said to be buying
B. is said to have bought
C. had said to buy
D. has said to have bought
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