题目

Rick has learned a lot about Chinese culture he came to China. A . before B . when C . until D . since 答案：D完全燃烧2.00g有机物，可生成4.40g CO2和1.44g H2O，则该有机物的化学式为（ ）A．C5H8B．C5H8OC．C5H8O2D．C10H16O4