Year 9 monsters

Year 9 drove me really mad today as they kept talking and joking with each other in English in my Chinese class and not matter how many times I stopped them, they started again immediately right after shutting for 10 seconds. It makes me almost throw them onto the wall, but of course I don't have strength to do so. Two English boys, one Korean boy, one Thai boy and two Korean girls form this class. The biggest problem is that the two English boys have much lower Chinese abilities than the others but they don't care and work hard to catch up with others. They behave almost like comedians who make fun of themselves and others, so that they have all the attention from their classmates. It makes me think if Y9 (14/15 years old) are the most rebellious year during one's teenage.