估计人类的四分之一深受原生动物性疾病之害。
It has been estimated that at any given moment a quarter of mankind is afflicted with severely debilitating protozoan diseases.
人类每年产生的温室气体中，约有四分之一是由世界的食物系统产生的。
The world's food system is responsible for about one quarter of the planet-warming greenhouse gases that humans produce each year.
但是，这却是人类基因组工程预算的四分之一。
But it is only about a quarter of what the Human Genome Project cost.
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