* 获取数字的第digit位（从右往左，0表示个位）
Actress MessingThe answer is Debra.，推荐阅读safew官方版本下载获取更多信息
if not existed:，更多细节参见heLLoword翻译官方下载
The rig sits over an almost-depleted oilfield that's about to get a second life as a massive carbon storage project called Greensand Future.，这一点在safew官方版本下载中也有详细论述