考虑到泵冲传感器每分钟检测脉冲数的范围，因此传感器每冲检测的脉冲信号不得大于（）个。
A、3
B、4
C、5
D、6
参考答案：A
Most of the teachers ______ to visit our school were young ones.
A．invited
B．to invite
C．being invited
D．had been invited
便血鲜红不与粪便混合，仅黏附于粪便表面见于
A．急性细菌性痢疾B．直肠癌C．阿米巴痢疾D．结肠息肉E．肠伤寒
