企业物流服务的水平决定于企业的（）。
A．生产系统
B．销售系统
C．物流系统
D．回收利用系统
参考答案：C
护锥冲毁加固一般用片石或石碴袋投下作基础，再在上面码砌装土草袋，作成临时护锥，保护桥头路基，流速小时，可沿锥体坡面根部铺石笼作基础。
They _____ on the little professor, but it led to his fierce criticism on us. [ ]
A. played a joke
B. made fun
C. had fun
D. performed a joke
