—I could have arrived much earlier, but I ____ in the traffic.

—What a pity![ ]

A. would be caught

B. was caught

C. has been caught

D. had been caught

术中判断心跳停止最可能的依据是（ ）。

A．大动脉搏动消失

B．立即观察瞳孔变化

C．数呼吸频率

D．用听诊器听心音

E．测血压