根据对话内容，在每小题的空白处写出一个完整的句子，使对话意思完整。

Emergency Operator: Police, Fire, Ambulance.

Dick: My name is Dick White.

Operator: 1.                             

Dick: D-I-C-K, W-H-I-T-E.

Operator: What's the problem?

Dick: I want to report a fire.

Operator: Stay on the line. I'll connect you with the fire department. Fire department, 2.                             . 

Dick: My address is 535 West 5th Avenue.

Operator: 3.                             .

Dick: The nearest corner is Pine St. and 5th Avenue.

Operator: 4.                             . 

Dick: It's an apartment not a house.

Operator: 5.                             . 

Dick: Third floor.

Operator: We're on our way.

测定聚合铝的PH值是（）。

A.取原液直接测定；

B.取原液的1%水溶液测定；

C.取原液10mL加90mL水混匀后测定；

D.取原液的5%水溶液测定