通常认为是无效成分或是杂质的是
A．皂苷类
B．树脂
C．萜类
D．氨基酸类
E．油脂
参考答案：B,D,E
---The girl is practicing English, ___________?
---Yes, she is. She is good at English.
A．is she
B．isn’t she
C．is the girl
D．doesn’t she
公民如何更改姓名？
