"STOP IT!! I really can't hold my temper!!" shouted Yoona in the Chemistry Lab. "You four will regret for doing this!" Tiffany said to Baekhyun, Kris, Luhan and Nichkhun. "I told you four to stop it earlier! See! Right now you four going to die." said Taeyeon with an angry face. "This is Yoona's favourite clothes and you guys spoiled it." Tiffany warned.

One hour ago

               "Morning unnie!" said Yoona happily, "Morning!" said Taeyeon, Jessica and Tiffany in unison. "Yoona, you seemed really happy today." said Taeyeon, "I think is because of this clothes." Tiffany guessed, "Yoona, tell us why are you so happy today." asked Jessica curiosly. "Because Kibum, my childhood friend, bought me a shirt and now I'm wearing it." Yoona smiled, "Oh, your boyfriend bought it." Jessica winked, "Unnie!! He is not my boyfriend, I like him as a brother. He really cares me since I'm young." protested Yoona, "Oh really?" smiled Taeyeon, "Yes!" Yoona said and quickly go to their classroom. Tiffany, Taeyeon and Jessica laughed while walking to their classroom. 

           The first lesson was Chemistry, so the class of students went to the Chemistry lab. After a few minutes, their teacher came in. "Good morning class," said Mrs.Lim. "Good morning, Mrs.Lim." greeted the students. "This lesson we will learn about H2O(water) and you will do the expeiment in a group of eight, four girls and four boys. You need to test with these substances." said Mrs.Lim while pointing at the table with some subtances on it. "First, mix the H2O with one of the substance and boiled it with bunsen burner. You have to do it one by one." Mrs.Lim told her students. "I'll tell you the arrangement right now. Kris, Baekhyun, Luhan, Nichkhun, Tiffany, Yoona, Taeyeon and Jessica in a group." announced Mrs.Lim, "What?!" shouted the eight in unison. "Eight of you don't want to be a group?" asked Mrs.Lim, "Of course......" Taeyeon was cut off by Baekhyun, "Of course not! We want to be in a same group." smirked Baekhyun, "I don't want!" said Jessica loudly, "Her meaning is she doesn'