Only when _____ in the afternoon _____ able to leave.   [ ]

A. the match was over; they were              

B. was the match over; were they  

C. was the match over; they were              

D. the match was over; were they

鲎试验用于测定

A．外毒素
B．内毒素
C．肠毒素
D．细胞毒素
E．抗毒素