试题与答案

效率率最低的是（）A、剑杆织机 B、有梭织机 C、喷气织机 D、多相织机

来源：www.tikuol.com
题型：单项选择题

题目：

效率率最低的是（）

A、剑杆织机

B、有梭织机

C、喷气织机

D、多相织机

答案：

参考答案：B

考点：纺织科学技术第八章打纬第八章打纬题库
试题推荐
题型：选择题

在光滑绝缘的水平地面上方，有两个磁感应强度大小均为B，方向相反的水平匀强磁场，如图所示的PQ为两个磁场的边界，磁场范围足够大。一个半径为a、质量为m、电阻为R的金属圆环垂直磁场方向，以初速度从如图位置向右自由平移，当圆环运动到直径刚好与边界线PQ重合时，圆环的速度为，则下列说法正确的是 （     ）

A．此时圆环中的电功率为

B．此时圆环的加速度为

C．此过程中通过圆环截面的电量为

D．此过程中回路产生的电能为
查看答案
题型：单项选择题

Questions 61-64 are based on the following passage.
"It’s like being bitten to death by ducks." That’s how one mother described her constant squabbles with her eleven-year-old daughter. And she’s hardly alone in the experience. The arguments almost always involve mundane matters—taking out the garbage, coming home on time, cleaning up the bedroom. But despite its banality, this relentless bickering takes its adolescents—particularly mothers—report lower levels of life satisfaction, less marital happiness, and more general distress than parents of younger children. Is this continual arguing necessary
For the past two years, my students and I have been examining the day-to-day relation-ships of parents and young teenagers to learn how and why family ties change during the transition from childhood into adolescence. Repeatedly, I am struck by the fact that, despite considerable love between most teens and their parents, they can’t help sparring. Even in the closest of families, parents and teenagers squabble and bicker surprisingly often—so often, in fact, that we hear impassioned recountings of these arguments in virtually every discussion we have with parents or teenagers. One of the most frequently heard phrases on our interview tapes is, "We usually get along but..."
As psychologist Anne Petersen notes, the subject of parent-adolescent conflict has generated considerable controversy among researchers and clinicians. Until about twenty years ago, our views of such conflict were shaped by psychoanalytic clinicians and theorists, who argued that spite and revenge, passive aggressiveness and rebelliousness toward parents are all normal, even healthy, aspects of adolescence. But studies conducted during the 1970s on samples of average teenagers and their parents (rather than those who spent Wednesday afternoons on analysts’ couches) challenged the view that family storm and stress was inevitable or pervasive. These surveys consistently showed that three-fourths of all teenagers and parents, here and abroad, feel quite close to each other and report getting along very well. Family relations appeared far more pacific than professionals and the public had believed.

The author’s own discoveries from the day-to-day relationships of parents and young teenagers indicate that ______.

A．storm and stress between the parents and the teenagers are normal

B．storm and conflicts are unavoidable

C．parents can never avoid the conflicts unless they love their children

D．parents’ strictness lead to their children’s disapproval of them
查看答案
微信公众账号搜索答案