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【简答题】
在平面四边形 中，已知 ， ，点 分别在边 上，且 ， ，若向量 与 的夹角为 ，则 的值为 .
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举一反三
【多选题】单片机片外总线结构由以下几部分组成( )
A.
位置总线
B.
控制总线
C.
地址总线
D.
数据总线
查看完整题目与答案
【单选题】Which of the following statements best supports the claim that organisms share fundamental processes as a result of evolution?
A.
All organisms that are introduced into new environments have the capacity to fill vacant ecological roles.
B.
All organisms have the ability to utilize oxygen to harness energy from the chemical breakdown of organic compounds.
C.
All organisms share a genetic code organized into triplet codons, it possible for one organism to express a gene from another organism.
D.
All organisms possess structures such as chloroplasts and mitochondria within their cells that reflect past symbiotic relationships between prokaryotic precursors.
查看完整题目与答案
【单选题】In the brain, only __________ of the nervous system that provide nutrients, support, and insulation for neurons—express glutamine synthetase.
A.
neurons
B.
astrocytes
C.
stem cells
D.
glial cells
查看完整题目与答案
【多选题】单片机片外总线结构由以下几部分组成 ( )
A.
控制总线
B.
数据总线
C.
位置总线
D.
地址总线
查看完整题目与答案
【多选题】Commonly used reporter genes that induce visually identifiable characteristics usually involve fluorescent and luminescent proteins, including:
A.
the gene that encodes jellyfish green fluorescent protein (GFP), which causes cells that express it to glow green under blue light
B.
the enzyme luciferase, which catalyzes a reaction with luciferin to produce light
C.
the red fluorescent protein from the gene dsRed
D.
the
E.
coli lacZ gene, which encodes the protein β -galactosidase. This enzyme causes bacteria expressing the gene to appear blue when grown on a medium that contains the substrate og X-gal
查看完整题目与答案
【多选题】下面关于unix的描述正确的是（）
A.
cat用于显示文本文件内容
B.
more用于分页显示程序或者文本
C.
使用chmod777可以改变文件访问权限为属主、用户组、其他人都可读可写可执行
D.
使用chmod ugo+rwx abc.c表示改变文件abc.c访问权限为属主、用户组、其他人都可读可写可执行
查看完整题目与答案
【单选题】维持血糖浓度相对稳定的人体功能基本调节方式是
A.
神经调节
B.
正反馈调节
C.
体液调节
D.
自身调节
查看完整题目与答案
【单选题】In ______, Theodore Friedmann and Richard Roblin published an important paper in Science [175(4025): 949-955] describing the use of gene therapy. Friedmann and Roblin described how they induced mammal...
A.
1965
B.
1969
C.
1972
D.
1975
查看完整题目与答案
【多选题】大气中NO,NO2和O3之间存在着的化学循环是大气光化学反应的基础,下面那些化学反应与之相关。
A.
NO2 + hv→NO + O●
B.
O●+ O2 + M→O3  +M
C.
O3 + NO→NO2 + O2
D.
以上均不是
查看完整题目与答案
【单选题】易化扩散的特点不包括
A.
特异性
B.
顺浓度进行
C.
饱和性
D.
消耗能量
查看完整题目与答案
相关题目：
【多选题】单片机片外总线结构由以下几部分组成( )
A.
位置总线
B.
控制总线
C.
地址总线
D.
数据总线
查看完整题目与答案
【单选题】Which of the following statements best supports the claim that organisms share fundamental processes as a result of evolution?
A.
All organisms that are introduced into new environments have the capacity to fill vacant ecological roles.
B.
All organisms have the ability to utilize oxygen to harness energy from the chemical breakdown of organic compounds.
C.
All organisms share a genetic code organized into triplet codons, it possible for one organism to express a gene from another organism.
D.
All organisms possess structures such as chloroplasts and mitochondria within their cells that reflect past symbiotic relationships between prokaryotic precursors.
查看完整题目与答案
【单选题】In the brain, only __________ of the nervous system that provide nutrients, support, and insulation for neurons—express glutamine synthetase.
A.
neurons
B.
astrocytes
C.
stem cells
D.
glial cells
查看完整题目与答案
【多选题】单片机片外总线结构由以下几部分组成 ( )
A.
控制总线
B.
数据总线
C.
位置总线
D.
地址总线
查看完整题目与答案
【多选题】Commonly used reporter genes that induce visually identifiable characteristics usually involve fluorescent and luminescent proteins, including:
A.
the gene that encodes jellyfish green fluorescent protein (GFP), which causes cells that express it to glow green under blue light
B.
the enzyme luciferase, which catalyzes a reaction with luciferin to produce light
C.
the red fluorescent protein from the gene dsRed
D.
the
E.
coli lacZ gene, which encodes the protein β -galactosidase. This enzyme causes bacteria expressing the gene to appear blue when grown on a medium that contains the substrate og X-gal
查看完整题目与答案
【多选题】下面关于unix的描述正确的是（）
A.
cat用于显示文本文件内容
B.
more用于分页显示程序或者文本
C.
使用chmod777可以改变文件访问权限为属主、用户组、其他人都可读可写可执行
D.
使用chmod ugo+rwx abc.c表示改变文件abc.c访问权限为属主、用户组、其他人都可读可写可执行
查看完整题目与答案
【单选题】维持血糖浓度相对稳定的人体功能基本调节方式是
A.
神经调节
B.
正反馈调节
C.
体液调节
D.
自身调节
查看完整题目与答案
【单选题】In ______, Theodore Friedmann and Richard Roblin published an important paper in Science [175(4025): 949-955] describing the use of gene therapy. Friedmann and Roblin described how they induced mammal...
A.
1965
B.
1969
C.
1972
D.
1975
查看完整题目与答案
【多选题】大气中NO,NO2和O3之间存在着的化学循环是大气光化学反应的基础,下面那些化学反应与之相关。
A.
NO2 + hv→NO + O●
B.
O●+ O2 + M→O3  +M
C.
O3 + NO→NO2 + O2
D.
以上均不是
查看完整题目与答案
【单选题】易化扩散的特点不包括
A.
特异性
B.
顺浓度进行
C.
饱和性
D.
消耗能量
查看完整题目与答案
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