A:She's a worker.
B:I am a student.
English has a large ____ (词汇) with different usage so it's not easy for a Chinese person to speak English as ____ (流利地) as a native English speaker.
下列选项中,脂质不可能具有的功能是( )
①参与生物膜构成 ②调节代谢 ③携带遗传信息 ④储存能量 ⑤细胞代谢中的直接能源物质.