自律性最高的是( )
A．窦房结B．心房肌C．房室交界D．心室肌E．普肯耶纤维
参考答案：A
解析：(2001年考试真题)
_____ homework did we have to do that we had no time to take a rest. [ ]
A. So much
B. Too much
C. Too little
D. So little
零售包装抗萌剂及植物生长调节剂
