测得某样品的含氮量为8g/L，则该样品蛋白质的浓度约为
A．40g/L
B．45g/L
C．50g/L
D．57.5g/L
E．62.5g/L
参考答案：C
Ten____________ people visit the museum_________________.
A. thousand; every day B. thousands; every day
C. thousand; everyday C. thousands; everyday
凉水塔回水温度偏低2℃左右，经检查热阻和显示仪表无问题，现场热阻的接线如图，试分析原因？
