速率散射比浊法测定是在()

A．抗原抗体反应的稳定阶段

B．终点比浊

C．抗原抗体反应的第一阶段

D．抗原抗体反应的第二阶段

E．以上均不对

—Was ________ problem solved?

—We were trying to think of ________ way out, but it was difficult to find one.

A．a; a

B．a; the

C．the; a

D．the; the