This is referred to as the struggle for existence. 这通常称为生存竞争。
Those variants will be preserved in the struggle for existence. 这些变异将在生存竞争中被保留下来。
Facing extinction, the elephants struggle for existence everyday. 面对绝种问题，大象每天都要和生存竞争。
In the wild struggle for existence, we want to have something that endures. 在激烈的生存竞争中，我们想获得一些耐受力强的东西。
The struggle for existence, in the case of the newspaper, has been a struggle for circulation. 生存竞争就报纸来说，乃是为报纸得发行而斗争。
This small food factory reduced their product prices to struggle for existence in the local market. 这个小食品厂为了在当地市场中求得生存，降低了产品价格。
The revolting army put forward the slogan of"save the nation; struggle for existence", which helped them win the love of the masses. 起义军打着救国图存的旗号，深得民心。