非零向量OA与OB，对于任意的t∈R，|OA+tOB|的最小值的几何意义为___

阅读理解。

     Do you know about the flu? The flu usually spreads quickly. In winter, lots of people may get the flu.

If you get sick, do you know what to do? Here are some tips.

     Drink lots of water. Water is good for your body when you get the flu.

     Get plenty of sleep. If you can't sleep, you can listen to music, watch a movie or read a book to relax

yourself.

      If you feel serious, ask your parents to take you to see a doctor. But don't take medicine until you see a

doctor.

     Wash your hands often! You certainly don't want to spread the flu to anyone else. Also, don't share cups

and eating utensils (用具), like forks, with other people.

      Most people will get better without seeing a doctor, but it will take them about a week to get well. If you

have a high temperature for more than a few days, call your doctor at once.

1. The underlined word "tips" means ______ in Chinese.

A. 末端

B. 建议

C. 小费

D. 垃圾

2. What should you drink to keep healthy?

    _____________________________________________________

3. How can you relax yourself if you can't sleep?

   ______________________________________________________

4. Must you see the doctor if you don't get the serious flu? 

   ______________________________________________________

5. :将文中画线的句子译成汉语。

   ______________________________________________________

组织中的成员在职学习可以（）。

以下程序运行后的输出结果是 _______ 。struct NODE{int k;struct NODE *link;};main(){struct NODE m[5],*p=m,*q=m+4;int i=0; while(p!=q){ p->k=++i; p++; q->k=i++; q--; } q->k=i; for(i=0;i<5;i++) printf("%d",m[i].k);printf("\n"); }

如图所示是小型建筑工地上使用的“罐笼式”提升机，用它能将放在罐笼A中的建筑材料提升到高处。已知被提升的建筑材料的质量为280kg，拉力F将它以0.5m/s的速度匀速提升到10m的高度，拉力F的功率为2kW。不计摩擦及钢丝绳、动滑轮的重。求：

（1）拉力F对所提升的建筑材料做的功是多少？

（2）罐笼A的重力是多少？

（3）提升机在提升建筑材料时的机械效率是多少？

形状特殊的的孔型或轧件在轧制过程中迫使金属有较大的宽展，这种宽展称为（）。

A、自由宽展

B、限制宽展

C、强迫宽展

D、以上都是