mean effectiveness

例句：

1. 1. This means that we need to work harder.
   这意味着我们需要更努力工作。
2. 2. The meaning of life is to live it fully.
   生活的意义是活得充实。
3. 3. The mean streets are where the poor live.
   贫民窟就是那些穷人住的地方。