class DatabaseStorage {
（二）提供网络交易服务的，应当采取监测发现、防范、阻断、处置销售或者拼装违禁物品、管制物品以及虚假交易等违法、可疑交易行为的措施；
，这一点在heLLoword翻译官方下载中也有详细论述
“Immigrants, just by showing up, they’re reducing the debt-to-GDP [ratio], and that’s a good thing for the country,” David Bier, Cato’s director of immigration studies and one of the report’s coauthors, previously told Fortune.
this.arr = []; // 存储所有历史价格，通过索引快速获取对应价格