单选题Which of the following may hardness of the boiler water cause?（） (1) scale formation (2) tube failure (3) corrosionA（1）and（2）B（1）and（3）C（2）and（3）D（1），（2）and（3）
单选题
Which of the following may hardness of the boiler water cause?（） (1) scale formation (2) tube failure (3) corrosion
A
（1）and（2）
B
（1）and（3）
C
（2）and（3）
D
（1），（2）and（3）
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