题目内容
（请给出正确答案）
[主观题]
将某班每个学生的英语考试成绩都增加10分，与原来相比其平均数和标准差的变化是（)。
A.平均数不变，标准差不变
B.平均数和标准差都增加10分
C.平均数增加10分，标准差不变
D.平均数不变，标准差增加10分
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题目内容
（请给出正确答案）
A.平均数不变，标准差不变
B.平均数和标准差都增加10分
C.平均数增加10分，标准差不变
D.平均数不变，标准差增加10分
答案
更多“将某班每个学生的英语考试成绩都增加10分，与原来相比其平均数和标准差的变化是（)。”相关的问题
第2题
A.小李可能去北京、小李必然不去北京
B.参加会议的都是领导干部、参加会议的没有一个是领导干部
C.甲和乙都懂英语、甲不懂英语或是乙不懂英语
D.小张是法律系学生，小张是哲学系学生
E.任何知识都来自实践，绝大多数知识来自实践
第4题
某班50名学生，包括30名女生，随机抽取一名学生恰好是男生的概率为()。
A1/20
B1/30
C3/5
D2/5
第8题
将英语短文译为中文
2. Kin Recognition (10分)
Many organisms, from sea squirts to primates, can identify their relatives. Understanding how and why they do so has prompted new thinking about the evolution of social behavior. by David W. Pfennig and Paul W. Sherman Kinship is a basic organizing principle of all societies. Humans possess elaborate means by which to identify relatives, such as using surnames and maintaining detailed genealogies.
Mechanisms for distinguishing kin also occur throughout the plant and animal kingdoms regardless of an organism’s social or mental complexity, in creatures as diverse as wildflowers and wasps. Scientists are beginning to discover that an understanding of the origin and mechanisms of kin recognition offers fresh insights into such diverse topics as how living things choose their mates, how they learn and how their immune system works.
BELDING’S GROUND SQUIRRELS live in groups in which mothers, daughters and sisters cooperate extensively. By using odors, the squirrels can distinguish familiar nestmates, who are close kin, from nonnestmates. They can also discriminate between full sisters and half sisters.
第9题
【案例】“差生”的成绩
我是差生行列中的一员，我也曾努力过，刻苦过，但最后却被一盆盆冷水浇得心灰意冷。就拿一次英语考试来说吧，我学英语觉得比上青天还难，每次考试不是个位数就是十几分，一次教师骂我是蠢猪，我一生气下决心下次一定要考好。于是，我加倍努力，真的拿了个英语第一名。心想这次老师一定会表扬我了吧!可是出乎我意料，老师一进教室就当着全班同学的面问我：“你这次考的这么好，不是抄来的吧？”听了这话，我一下子从头凉到脚，难道我们差生就一辈子都翻不了身了吗？
问题：
透过这份案例，深切地感受到学生对现行评价制度和评价方法的恐惧，不满与无奈。现行课程评价存在哪些主要问题？
第10题
A.错误
B.正确
第11题
将英语短文译为中文
3 Self-Powered Nanotech (10分)
Nanosize machines need still tinier power plants
By Zhong Lin Wang
The watchmaker in the 1920s who devised the self-winding wristwatch was on to a great idea: mechanically harvesting energy from the wearer’s moving arm and putting it to work rewinding the watch spring.
Today we are beginning to create extremely small energy harvesters that can supply electrical power to the tiny world of nanoscale devices, where things are measured in billionths of a meter. We call these power plants nanogenerators. The ability to make power on a minuscule scale allows us to think of implantable biosensors that can continuously monitor a patient’s blood glucose level, or autonomous strain sensors for structures such as bridges, or environmental sensors for detecting toxins — all running without the need for replacement batteries. Energy sources are desperately needed for nanorobotics, microelectromechanical systems (MEMS), homeland security and even portable personal electronics. It is hard to imagine all the uses such infinitesimal generators may eventually find.
In Brief
★Nanotechnology has huge potential — but those minuscule devices will need a power source that is better than a battery.
★ Waste energy, in the form. of vibrations or even the human pulse, could provide sufficient power to run such tiny gadgets.
★ Arrays of piezoelectric nanowires could capture and transmit that waste energy to nanodevices.
★ Medical devices will likely be a major application. A pacemaker’s battery could be charged so it would not need replacing, or implanted wireless nanosensors could monitor blood glucose for diabetics.
