金属材料的内部夹杂，表面光洁度低，有刀痕或磨裂等，会使材料疲劳强度降低-我要搜题网

[单选题]【42055】在变压器中性点装设消弧线圈的目的是( )。 ( )
A.提高电网电压水平
B.限制变压器故障电流
C.补偿电网接地的电容电流
D.吸收无功

[单项选择]在IR序列中，如果某一组织的T1值接近反转时间，则该组织在图像上表现为（）。
A. 信号增强
B. 信号较强
C. 信号抑制
D. 中等信号
E. 无信号

[填空题]学前儿童典型的游戏形式是（），是幼儿阶段最常见的。

[单选题]Back in the old days, when I was a child, we sat around the family round table at dinnertime and exchanged our daily experiences. It wasn't very organized, but everyone was recognized and all the news that had to be told was told by each family member. We listened to each other and the interest was not put-on; it was real. Our family was a unit and we supported each other, and nurtured each other, and liked each other, and--we were even willing to admit--we loved each other. Today, the family round table has moved to the local fast-food restaurant and talk is not easy,much less encouraged. Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old. So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I'm busy, go watch television. " And watch TV they do; count them by the millions. But it's usually not children's television that children watch. Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing. Where are they to be found? Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch. That's where you find our kids, over five million of them, at 10 p.m., not fewer than a million until after midnight! All of this is done with parental permission. Television, used well, can provide enriching experiences for our young people, but we must use it with some sense. When the carpet is clean, we turn off the vacuum cleaner. When the dishes are clean, the dishwasher turns itself off. Not so the television, which is on from the sun in the morning to the moon at night and beyond ! Parents must exercise some control and show some concern about the cultural influence on the child whena program not intended for that child is viewed.Parents need to intervene. Nonintervention may be a wise policy in international affairs,but the results of parental nonintervention will not be wise at all. From the first two paragraphs one may infer that the writer's attitude towards "the old days" is__________.
A.preferring
B.hating
C.being tired of
D.disappointing

[判断题]金属材料的内部夹杂，表面光洁度低，有刀痕或磨裂等，会使材料疲劳强度降低。

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