昆虫像其他节肢动物一样,体分节,附肢有主节,具有外骨骼。鉴别特征为︰头部有口,无步行肢,生殖孔接近肛门;在发育中通常有变态现象。世界的昆虫种类大约有1000万种以上。而且现在已被人类认知的昆虫大约100万种,只占其中极少一部分。昆虫通常是中小型到极微小的无脊椎生物,是节肢动物的最主要成员之一。昆虫最大的特征就是身体可分为三个不同区段:头、胸和腹。它们有六条相连接的脚,而且通常有两对翅膀贴附于胸部。[展开全部]
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In the backwoods of Ontario lies a town called Kinmount. This little hamlet of only a few hundred residents no longer has a gas station or a school; however, thanks to the singular vision of local septuagenarian Keith Stata, what it does boast is a five-screen cinema palace and memorabilia museum—one that welcomes upwards of 50,000 visitors every summer.
Join visionary philanthropist Bill Gates as he delves into pressing global issues and uncovers cutting-edge technologies that will transform the world.
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更多In the backwoods of Ontario lies a town called Kinmount. This little hamlet of only a few hundred residents no longer has a gas station or a school; however, thanks to the singular vision of local septuagenarian Keith Stata, what it does boast is a five-screen cinema palace and memorabilia museum—one that welcomes upwards of 50,000 visitors every summer.
Join visionary philanthropist Bill Gates as he delves into pressing global issues and uncovers cutting-edge technologies that will transform the world.