Mr. Li regards Ningxia as his second_______ because he has been here for over twenty years.

A．family

B．house

C．room

D．home

在进行建设项目环境验收监测的噪声考核工作时，需进行昼夜等效声级的计算；由于噪声在夜间比昼间影响大，故计算时需要将夜间等效声级加上（）D．B．后再计算。

A．5 

B．8 

C．10 

D．12