The creation of life requires a set of chemical elements for making the componen

游客2024-01-02  17

问题 The creation of life requires a set of chemical elements for making the components of cells. Life Earth uses about 25 of the 92 naturally occurring chemical elements, although just 4 of these element oxygen, carbon, hydrogen, and nitrogen—make up about 96 percent of the mass of living organis Thus, a first requirement for life might be the presence of most or all of the elements used by life.
The phrase "these elements" refers to ________.

选项 A、25 of the 92 naturally occurring chemical elements
B、the 92 naturally occurring chemical elements
C、the mass of living organisms
D、oxygen, carbon, hydrogen, and nitrogen

答案 A

解析 上文第2句中状语从句出现了these elements,其所指应往前找。前面提到地球上的生命仅用到了 25 of the 92 naturally occurring chemical elements,而although引导的从句进一步指出,在这需要用到的25种元素中,仅4种便可组成地球上96%的生命。因此,these elements应指代上文的25 of the 92 naturally occurring chemical elements有干扰性的是B项,但从第3句中的most or all of the elements used by life也可确认,这里指的是地球上的生命需要用到的25种元素,而不是92种元素,故A项更贴切。
转载请注明原文地址:https://tihaiku.com/zcyy/3327710.html
最新回复(0)