没有孩子的民族将面临无望的未来，而没有树木的国家将面临更无望的未来。
A people without children would face a hopeless future; a country without trees would face a future with even less hope.
释义：船装载过重就会沉没，人欲望太强就会损害生命。劝诫人要节制自己的欲望。
提供上下文，而非控制。
The key to performance is to keep the hot data in memory.