Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient ...

Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient ...

现在我们周围的环境污染越来越严重。作为一个中学生，我们应节约资源，保护环境，从我们身边的小事做起，做一个“低碳生活”的中学生。请以“My Low--carbon Life”为题，写一篇短文描述自己的“低碳生活”。

See? “By” originally means “bye” or byway. That’s why, in fact, some people still spell “by the by” as “by the bye”. By the ...

• 儿童和青少年： 15-19岁青少年癌症发病率持续上升，14岁及以下儿童的发病率有所下降。1970年以来，儿童癌症死亡率下降了70%，青少年死亡率下降了63%，很大程度上因为白血病治疗手段进步。