如图所示，两木块的质量分别为m₁和m₂，两轻质弹簧的劲度系数均为k，上面木块压在上面的弹簧上（但不拴接），整个系统处于平衡状态．现缓慢向上提上面的木块，直到它刚离开上面弹簧．则上述过程中，下面木块上升的距离为____、上面木块上升的距离为____．

Saturday, February 25th

    The Turn off (关掉) TV Week starts today. People who organize (组织) it say that TV is a bad thing. I' m not sure if they're 1 .

First of all, the organizers say that children today are in bad physical condition (身体状况) because they 2 almost all their free time in front of the TV. But a 3 of 10,000 American children aged 10 to 15 found no connection (联系,) between TV and physical health. Children who don't watch TV don't always do more 4 .

    Of course, there are some terrible programs on TV. 5 I don't think we should say no to TV. We 6 need to choose programs good for us ourselves. Another 7 that the organizers agree on （同意) is that TV stops us from talking with others. An American study found that parents in homes with no TV had an hour of talk with 8 children every day. In other homes, there was only 38 minutes of talk …… a week! That's bad. But TV can also bring people together and 9 to start a talk. Is there a better way to start a talk than by talking about, the latest popular programs?

    Turn off my TV? OK. But I also10 to turn it on when there's something good on.

我能判断对。

循环小数都小于1。

平面四边形ABCD中，AD=AB=$\sqrt{2}$,CD=CB=$\sqrt{5}$,且$AD\perp AB$，现将$△ABD$沿着对角线BD翻折成$△A^{\text{'}}BD$，则在$△A^{\text{'}}BD$折起至转到平面$BCD$内的过程中，直线$A^{\text{'}}C$与平面$BCD$所成的最大角的正切值为(   )