生物与环境相互依赖、相互影响。下列哪一项体现了生物影响环境？ A．人间四月芳菲尽，山寺桃花始盛开 B．朵朵葵花向太阳 C．千里之堤，溃于
今有如下三个热化学方程式： (1)H2(g)＋O2(g)===H2O(g) ΔH1＝a kJ·mol－1 (2)H2(g)＋O2(g)===H2O(l) ΔH2＝b kJ·mol－1 (3)2H2(g)＋O2(g)===2H2O(l) ΔH3＝c kJ·mol－1 下列关于它
20种氨基酸的平均分子量为128，现有一蛋白质分子由两条肽链组成，共有48个肽键，此蛋白质的相对分子量最接近于 A.6400 B.5550
下列现象由地球自转产生的是（ ） A．四季变化 B．五带形成 C．极昼极夜 D．昼夜更替
若等比数列{an}的各项均为正数，且a10a11＋a9a12＝2e5，则lna1＋lna2＋…＋lna20＝________.
Stephen used to work in a company. Unluckily, he got serious heart disease. He couldn't work for a long time. Thinking he could still do something for others, he decided to be a volunteer(志愿者) a
At first, the students discussed the questions all in English, but after a while, they ______speaking in Chinese. A. gave up B. picked up C. turned
=_______________。