Recently a very strange phenomenon come into being around me. Some of my friends and classmates often fart and belch in public wherever we are in classroom, refectory, walking on the sidewalk or talking in the dormitory. They belch loudly as if they are having a competition and have brewed for a long time. Just a moment ago, when i was browsing your blogs, one of my roommates said“keep quite, I have something special for you”. His waist bent , his fist stopped in the air and his face was decorated with seriousness as if something is gonna happen.When I was hoping for “something special”, he burst into a big, loud and longlasting fart ！After a short silence, we roared with laughter and that lasted for a few second. I also clearly recall the sonorous belch in my statistics class. And the whole class including the teacher burst into laughter. Sometimes,  they even intentionally belch and fart. What'more, some creative guys invented the manmade belch so that they can belch at anytime they like. They hold some air in their throats by swallowing gas. When they can no longer suppress they vomit all the air in one breath. Then the artificial belch is finished. I am really surprised at their creativity!I admit that these unexpected sounds really entertain us, but some are not in the right place.