题干

如图所示,电源电压恒为6V,滑动变阻器R′的最大阻值为30Ω,当S闭合,滑片P在最右端时,电压表的示数为1.5V,则小灯泡L的电阻是____Ω,当滑动变阻器的滑片P移到a点时,电压表的实数为Ua,滑动变阻器的功率为Pa;再移动滑片P到b点时,电压表的示数为Ub,滑动变阻器的功率为Pb,若Ua:Ub=2:3,Pa:Pb=8:9,则滑动变阻器的滑片p在a,b两点时连入电路的电阻变化了____Ω(不计灯丝电阻随温度的变化)

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    Do parents owe their kids anything? Starting from my position, parents do not owe their children a 1 education. If they can 2 it, they can 3send them to the best universities. But they must not feel guilty if they can't. If the children really want to go, they'll find a 4. There are plenty of loans (贷款) and scholarships for the bright and 5 ones who can't afford to pay.

    When children grow up and want to 6, their parents do not owe them a down payment on a house. They do not have the 7 to baby-sit their grandchildren. If they want to do it, it must be considered a 8 not a responsibility.

    Do parents owe their children anything? Yes, they owe them a great deal.

    One of their duties is to give their children a personal 9. A child who is constantly made to feel stupid and unworthy, constantly 10 to brighter brothers, sisters, or cousins will be so 11, so afraid of failing that he (or she) won't try at all. Of course they should be 12 corrected when they do wrong, but it's often better to let children learn their mistakes by themselves 13. All our parents should do is to trust them, respect them, tolerate (宽容) them and give them chances to try and fail. They must learn to stand 14. When criticisms (批评) are really needed, they should be 15 with praises, with a smile and a kiss. That is the way children learn.

    Parents owe their children a set of solid values around 16 they build their lives. This means teaching them to 17 the rights and opinions of others; it means being respectful to elders, to teachers, and to the law. The best way to teach such values is by 18. A child who is lied to will lie. A child seeing no laughter and no love in the home will have 19 laughing and loving.

    No child asks to be 20. If you bring a life into the world, you owe the child something.