physics questions read and revise

1. 270 How do insects run on the surface of the water?
2. 270 Why hot water is preferable than cold water for washing clothes/
3. 272 
4.  271State and prove Bernoulli's theorem
5. 273 why two holes are made to empty an oil can?
6. if you stand near the running train on the platform there is a danger of falling towards the train.why?
7. 275 Define Young's modulus.
8. 276 Define Pascal's law
9.