按下列各小题括号内的要求改写句子，每空限填一词。
1. Meimei has to look after her little brother at weekends. (改为一般疑问句)
________ Meimei ________ to look after her little brother at weekends?
2. Both he and his deskmate have passed the exam. (改为否定句)
________ he nor his deskmate ________ passed the exam.
3. Let us stop and have a rest, ________?(完成反意疑问句)
4. We have fine weather today. (改为感叹句)
________ ________ weather we have today!
5. They are asked to write a diary in English every other day. (就划线部分提问)
________ ________ are they asked to write a diary in English?
6. Didn't they tell you about it? (改为被动语态)
________ you ________ about it?
7. Will the 29th Olympic Games be held in Beijing? Could you tell me? (合并成含有宾语从句的复合句)
Could you tell me ________ the 29th Olympic Games ________ be held in Beijing?
的斜面上的物块P，由跨过定滑轮的轻绳与物块Q相连，从滑轮到P、Q的两段绳都与斜面平行。已知Q与P之间、P与斜面之间的动摩擦因数都是μ，两物块的质量都是m，滑轮的质量、滑轮轴上的摩擦都不计。若用一平行斜面向上的力F拉P使它做匀速运动，则F的大小
