动词形式是affect，名词形式是effectiveness，副词形式是effectively，例如：
1、Television is an effective means of communication.电视是一种有效的通信手段。
2、It has been demonstrated that this drug is effective.这药已证实是有效的。
3、Cooperative activity is essential to effective community work.要把社区工作做好，协作活动是必不可少的。
