问题描述：
plain green
原文是这样的,Most British telephone cards are just plain green,but card collecting is becoming a popular hobby in Britain and collectors even have their own magazine,International Telephone Cards.这里plain green
原文是这样的,Most British telephone cards are just plain green,but card collecting is becoming a popular hobby in Britain and collectors even have their own magazine,International Telephone Cards.这里plain green
问题解答：
我来补答展开全文阅读