adj.不需要的；无用的
Banning smoking would save needless deaths. 禁止吸烟会免除不必要的死亡。
If one is enough, a second although useful is needless. 如果一个够了，那么第二个即使有用，也是不需要的。
Needless to say, he kept his promise. 不用说，他信守了他的诺言。
Needless to say, learning without thinking is useless. 不用说，学而不思则罔。
adv.毫无必要地
