Nitrates are chemicals that occur naturally in water and the soil.
硝酸盐是水和土壤里天然存在的化学物质。
Some changes in DNA occur naturally and lead to no harmful effects;
有些DNA的变化是自然发生的不会产生有害影响；
Vitamins are nothing more than 5 chemicals that occur naturally in food.
维生素只不过是在食物中天然存在的化学品。
The pig is the only animal in which hog cholera is known to occur naturally.
猪是已知自然发生猪瘟的唯一动物。
They occur naturally but biochemists can make synthetic versions.
它既能自然合成，也可通过生物化学家人工合成。
The process of desertification can also occur naturally.
自然情况下也存在土地荒漠化过程。
Miracles occur naturally as expressions of love.
奇迹以爱的表达方式自然发生。
Repressed emotions do not occur naturally, during evolution.
压抑情感不是在进化过程中自然出现的。
Repressed emotions do not occur naturally, during evolution.
压抑情感不是在进化过程中自然出现的。
应用推荐