①以碳链为基本骨架 ②与双缩脲试剂反应呈蓝色
③促进肝糖原分解 ④由胰岛B细胞合成、分泌
A:①③
B:①④
C:②③
D:③④
— If you break your word, she will never trust you again.
— I see. I'll keep my word.