不定项选择发电厂发电机的输出电压为U1,发电厂至学校的输电线电阻为R,通过导线的

题型:不定项选择

问题:

不定项选择
发电厂发电机的输出电压为U1,发电厂至学校的输电线电阻为R,通过导线的电流为I,学校得到的电压为U2,下列计算线路损耗功率的式子中不正确的是(   )
A.U12/R

B.(U1-U22/R

C.I2R

D.I(U1-U2

考点:远距离输电的相关计算
题型:不定项选择

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多

余选项。

 小题1:

Examinations are almost always stressful. Students rarely know exactly what to expect on the test, and those who suffer from exam fear or exam anxiety can see their grades suffer as a result of this stress. For some students,exam fear causes them to “ seize up ’’ and forget what they have studied.

   小题2:   Good study habits and learning how to relax can help students overcome exam fear.

    小题3:    According to Penn State University and Kids Health,proper study habits and preparation are the keys to cutting out exam fear. Avoid last-minute “cramming” for exams and actively listen while in class.

Focus on positive thoughts, relax the night before your test and reward yourself after the test is over. Often, people who suffer from exam anxiety cannot shut out negative thoughts or emotions about the test, and this can contribute to feeling more anxiety than normal.    小题4:    . Keep your mind and body healthy by getting enough sleep, eating well and exercising. Healthier people who are well-rested often do better on exams.

    小题5:  Exam fear is normal When that anxiety severely interferes (干扰)with your ability to take the test, however, outside help might be needed. Ask your teachers and family for support and help.

A.How To Succeed in An Exam

B.How To Overcome Exam Fear

C.Develop good study habits.

D.Understand that you are not alone and ask for help if necessary.E. Remind yourself that it’s just one test and that you can get through it

F. Battling this type of performance anxiety can be hard, but it is not impossible.

G. Remind yourself to read the instructions carefully.

题型:不定项选择

氨基糖苷类抗生素的主要作用机制是

A.抑制细菌细胞壁的合成

B.干扰细菌的叶酸代谢

C.作用于细菌核蛋白体50S亚基,干扰蛋白质的合成

D.作用于细菌核蛋白体30S亚基,干扰蛋白质的合成

E.干扰细菌DNA的合成

题型:不定项选择

在计算企业所得税时,下列固定资产中不得提取折旧的是( )。

A.闲置的厂房

B.以经营租赁方式出租的厂房

C.以融资租赁方式租入的设备

D.以经营租赁方式租入的设备

题型:不定项选择

下述哪项描述符合细菌性角膜炎的特点()

A.发病有急有慢,症状可非常突出,也可较缓和,角膜溃疡病灶可表现为局灶性脓肿,也可表现为广泛的液化性坏死,还可表现为范围较小,进展缓慢的温和的溃疡灶

B.按照感染发生的部位,溃疡可浅层,也可为深层,且常常出现复发

C.由于感染角膜的细菌毒力强弱不同,角膜可出现单个溃疡灶或多个溃疡灶,单个溃疡灶可扩大融合为较大的溃疡灶

D.角膜溃疡病灶非常严重,但患者症状相对较轻

E.通常引起角膜炎的病因为细球菌科(葡萄球菌)、链球菌科(肺炎球菌)、假单胞菌科(铜绿假单胞菌)、念珠菌属、镰刀菌属、曲霉菌属等

题型:不定项选择

发电机的短路特性是指发电机制额定转速下,定子三相短路时,定子稳态()与()之间的关系曲线。

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