In an infinite dimensional space there always exist two subspaces whose vector sum is different from their span.
在一无限空间中恒存在两个子空间，其矢量和与其张成空间不同。
2
Her wings have a huge span that seems almost infinite to the beholder.
她的翅膀十分巨大，在外人看来好像无穷无尽一般。
3
The expected cost per unit -time for infinite time span is analyzed strictly under the mathematical model constructed, and the optimum age replacement decision is also discussed.