皮皮学,免费搜题
登录
搜题
【简答题】
When an ant dies, other ants take it out of the nest, often within an hour after its death. This behavior interests scientists and they wonder how ants know for sure—and so soon—that another ant is dead. One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead. But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet” when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait— I'm not dead yet” quickly goes away. When other ants detect the “dead” chemical without the “not dead yet” chemical, they move away the body. To test his theory, Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the “Wait—I'm not dead yet” chemical, other ants left the treated ant alone. Choe believes this behavior shows that the “not dead yet” chemical overrides the “dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining “dead” chemical and remove the body from the nest. Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】下列哪种方法用来解决不确定型决策问题的
A.
数学规划法
B.
大中取大法
C.
大中取小法
D.
网络优化法
【简答题】请把手工业务11月11-20日业务完成,并将答案上传。 要求:最好纸质答案拍照,注明学号和姓名。(保存做题记录,开学用)
【简答题】如下图所示,计算挂落的工程量。
【单选题】150梁平法施工图中KL10(5)支座通长筋为 。
A.
4 根直径为 20 mm的三级钢筋
B.
4根直径为22 mm的三级钢筋
C.
2根直径为20 mm的三级钢筋
D.
2根直径为22 mm的三级钢筋
【单选题】150 梁平法施工图中 KL10 ( 5 )支座通长筋为( )
A.
4C20
B.
4C22
C.
2C20
D.
2C22
【单选题】CD-ROM盘存储数据的原理是,利用在盘上压制凹坑的机械方法,凹坑的边缘用来表示________,而凹坑和非凹坑的平坦部分表示________,然后再使用________来读出信息
A.
“ 1 ” 、“ 0 ” 、激光
B.
“ 0 ” 、“ 1 ” 、磁头
C.
“ 1 ” 、“ 0 ” 、磁 头
D.
“ 0 ” 、“ 1 ” 、激光
【单选题】,一项新的减肥计划声称:在计划实施的第一周内,参加者的体重平均至少可以减轻8磅。为了检验这个结论,抽查人员抽取40位参加该项计划的样本,结果显示:样本的体重平均至少减少7磅,标准差为3.2磅,则其原假设和备择假设是()
A.
: , : 8
B.
: , : 8
C.
: , : 7
D.
: , : 7
【单选题】CD-ROM盘存储数据的原理是,利用在盘上压制凹坑的机械方法,凹坑的边缘用来表示________,而凹坑和非凹坑的平坦部分表示________,然后再使用________来读出信息
A.
“1”、“0”、激光
B.
“0”、“1”、磁头
C.
“1”、“0”、磁
D.
“0”、“1”、激光
【单选题】位周期中心的向上跳变代表0,位周期中心的向下跳变代表1为
A.
不归零制
B.
归零制
C.
曼切斯特编码
D.
差分曼切斯特编码
【简答题】CD-ROM盘存储数据的原理是,利用在盘上压制凹坑的机械方法,凹坑的边缘用来表示______,而凹坑和非凹坑的平坦部分表示______
相关题目: