—Could you tell me ________ tomorrow morning?

—Well, it will start at 9 o'clock. [ ]

A. when the meeting will start

B. when will the meeting start

C. when the meeting started

D. when did the meeting start

对人类而言属于异嗜性抗原的物质是（）

A.人抗白喉外毒素血清

B.BSA

C.破伤风抗毒素

D.ABO血型抗原

E.大肠杆菌O¹⁴