In1953 , when the writer entered the data processing field, he was to learn that electronic computers could perform several thousands additions per second.
A.
frightened
B.
embarrassed
C.
dismayed
D.
astounded
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【简答题】设向量组β 1 ,β 2 ,…,β m (m>1)可由向量组α 1 ,α 2 ,…,α m 线性表出为:β 1 =α 2 +α 3 +…+α m ,β 2 =α 1 +α 3 +…+α m ,…,β m =α 1 +α 2 +…+α m-1 .证明:向量组α 1 ,α 2 ,…,α m 的秩等于向量组β 1 ,β 2 ,…,β m 的秩.