I like physics, because in physics classes have many interesting Experiment. 

      Last weak, Mr. Li did one experiment show us, he till a jar with water.  He covered top with a piece of cardboard, then, he put his hard on the cardboard and turned the jar upside down. Next, Ms Li took his hand off the cardboard, the cardboard didn’t get wet.

     Mr. Li explains: “the atmospheric pressure upon the cardboard. It’s like water pushing up a boat the tore is strong enough to hold the water .The piston pump is use atmospheric pressure gain water. 

       Use physics know ledge you can do mange interesting Experiment.