Saida拥有一个石油公司的股份125股.一天,每股降了$0.31.第二天,每股升了$0.18.Saida的股份总价值变化了多少?$0.31 - $0.18 = $0.13 The value of each share dropped by $0.13 after the 2 days' changes in price$0...为什么是0.31-0.18 他那里是DROP0.31 那么不是-0.31-0.18一个道理啊，我后面说明了是drop的值啊The value of each share dropped by $0.13 after the 2 days' changes in price降得多，降的减升的，就是降的升得多，升的减降的，就是升的