for example, the regex [a-zA-Z] only cares about two kinds of characters: letters and everything else. so instead of individually taking derivatives for 52 alphabet characters a..z, A..Z, we can conclude from the start that there are only two kinds of characters we care about: letters ([a-zA-Z]) and non-letters ([^a-zA-Z]).
US lost 92,000 jobs in February just before Trump joined Iran conflict
，更多细节参见PDF资料
The iPhone 17e is here: 6 ways Apple just upgraded its cheapest phone
全年对外承包工程完成营业额12773亿元，比上年增长8.1%。其中，对共建“一带一路”国家完成营业额10902亿元，增长9.6%，占对外承包工程完成营业额比重为85.4%。对外劳务合作派出各类劳务人员43万人。
Second hand cars excluded from petrol and diesel ban