题目

从地理环境看，亚非早期区域文明分布的特点是( ) A . 以农业经济为主 B . 建立了统一的奴隶制国家 C . 地处大河流域 D . 创造出了属于自己的文字 答案：CE - mail, as well as telephones, ________ an important part in daily communication. 　　A．is playing 　　B．have played 　　C．are playing 　　D．play