嘧啶环中的两个氮原子来自A.谷氨酰胺和氨 B.谷氨酰胺和天冬酰胺 C.谷氨酰胺和谷氨 发布时间:2017-12-10 20:34 │ 来源:www.tikuol.com 题型:单项选择题 问题: 嘧啶环中的两个氮原子来自A.谷氨酰胺和氨B.谷氨酰胺和天冬酰胺C.谷氨酰胺和谷氨酸D.谷氨酸和氨甲酰磷酸
题型:单项选择题 Which of the following is NOT true about unwanted e-mail A.It costs money to receive them.B.It's free to store them.C.It takes time to access them.D.It takes time to throw them away. 查看答案