题目

下列化合物中，由相同元素组成的是 A. 纤维素、胰岛素、性激素    B. ADP、tRNA、质粒 C. 脂肪、丙酮酸、核苷酸    D. 抗体、酶、生长素 答案：B—Do you often play piano?—Yes. I want to be musician like Lang Lang.A. the; a B. a; the C. the; an