----I wonder_______.

----Of course. He began to prepare for it last month.

A．when will he give back the magazine to the library

B．whether he has prepared for the writing competition

C．what was he talking about with his friends

D．where he is going to hold the English party

糖链为葡萄糖的苷是（）

A．金丝桃苷

B．新橙皮苷

C．黄芩苷

D．葛根素

E．橙皮苷