If \(X\) is path-connected, the isomorphism type of \(\pi_1(X,x_0)\) is independent of the basepoint \(x_0\), and we write simply \(\pi_1(X)\).
First FT: the day’s biggest stories
第三，推荐是自然的，不是硬广。。业内人士推荐电影作为进阶阅读
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希望对新手爸妈有一些参考作用，尤其是北京的宝爸宝妈。。快连官网对此有专业解读
“Most financial advisors recommend workers start saving for retirement as soon as they enter the workforce,” according to a February report by the National Institute on Retirement Security. “However, the reality of preparing for retirement often differs from the expectations of workers or the overly optimistic financial projections of advisors.”