Objects in image: Whiteboard
Text visible in image: Expressions, zao, shang, has, gvam, zhong, gwo, Xin, lan, 2hong, ws, hao, 12:00, shaing, har, ranada, shang, hao, 7:0/p:vm, pm, Po, guotre, wan, bonne, mit, mei, gus, y, Tang, nY, zao, hro, dui, bu, 9%, 6, tu, ni, ST, wo, cing, Pa, gus, lai, xie, Xie, mei, gian, Ying, guo, bu, yong, xie, ben, han, guo, bu, ke, Ja, de, gno
Question: what is the main topic of the whiteboard lesson?
Answers: expressions, expressions, expressions, expressions, expressions, expressions, expressions, expressions, expressions, expressions