现场传感器是指带式输送机的各种保护信号，现场各种设备的运行返回信号，原煤仓的高低煤位信号等。
参考答案：对
It's the sort of work that ____ a high level of concentration. [ ]
A. calls for
B. makes up
C. lies in
D. stands for
受生物性污染的水体最易引起
A．介水传染病B．急性中毒C．慢性中毒D．公害病E．恶性肿瘤
