Thanks to the tutor’s guidance, by tutor’s guidance we learned PLA’s current research condition. Now we gained basic knowledge about this sphere of learning. Due to the tutor’s instruction, we got a clear cognition about science research. Which make us more rational. We also appreciate classmate’s help. We got lots of information by discussing with classmates. Thanks to the School of Natural and Applied Science. They provided a laboratory for us to do an experiment. Without their help, we can't finish this project.