单元独立系统就是用一套灭火剂储存装置，保护（）或（）的灭火系统。

My wife and I went to a supermarket, there we bought some cold drinks and cakes. After we came out of the supermarket, we noticed that in the front of the supermarket was a nice little garden with benches for people relax on. We sat there and started enjoying the things we have just bought. There was ten small cakes in the bag and we couldn’t eat all of it. I wanted to share, but of whom? A young boy appeared. He was looking into the trashcan for nothing to eat. We had just finished three of the ten cakes. So, I took the remained pieces and gave them to him. He thanked me and ran away in a happily mood.

点P在第四象限，到x轴的距离为3，到y轴的距离为2，则P点坐标为______．

已知年利率为15%，按季度计算，则年有效利率为( )。

A．12.55%

B．12.68%

C．15.86%

D．16.73%

收益性物业的经营费用是除( )外物业发生的所有费用。

A．人员工资
B．抵押贷款还本付息
C．保险费
D．房产税

对水体自净影响最大的两个因素为（）

A.水体对污染物的稀释和水体中溶解氧的变化

B.污染物和排放方式

C.天气状况与地理情况

D.排放量与排放时间