ladies teacher and classmate: Good morning. I have been for three years. Twenty stops. My name is Jane Huang. I want to thank my teachers and classmates for giving me this opportunity to conduct a
Now, coumarin is a very common thing, a material, in fragrance which is derived from a bean that comes from South America. 香豆素是香水中一个十分平常的原料，从来自南美的豆子中提炼出来的。 And it is the classic synthetic aroma chemic
