问题
多项选择题
下列属于集中趋势的计量指标有（）。
A.众数
B.中位数
C.算数平均数
D.方差
E.标准差
答案
参考答案：A, B, C
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下列属于集中趋势的计量指标有（）。
A.众数
B.中位数
C.算数平均数
D.方差
E.标准差
参考答案：A, B, C
Which came first, the chicken or the egg? This is one of life’s ______ questions and people have been debating about it for thousands of years. Now scientists believe they have solved this ______. Researchers from Sheffield and Warwick Universities in England discovered the answer ____. They used a super computer to observe the shell-making process while a new shell was ____. Then they found one protein called OC17 that is ______ for forming eggshell. This is only found inside a chicken’s body, which is proof that the ______ came first. The team was ______ looking at how animals and birds make eggshells but suddenly made their surprising ______. The big question now is where chickens came from. The ______ is from dinosaurs. The research team said eggshells are one of nature’s most ______ creations. Professor John Harding from the team told reporters: “Understanding how chickens make eggshells is fascinating in itself, but it can also be _____ in designing new materials.” Eggshells are very lightweight but incredibly strong. Even the most up-to-date materials _____ by the world’s top engineers cannot produce anything as ______ as an eggshell. Professor Harding added that ______ eggshells could help to cure bone diseases and design materials for the construction industry. “Nature has found wonderful ways that ___ for all kinds of problems in materials science and technology — we can learn a lot from them.” he said.
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