当处理水源pH值在（）左右时，由于腐蚀因素和净水效果的要求需进行pH值调节。
A.4.0
B.5.0
C.6.0
D.7.0
参考答案：B
________ my teacher didn't tell me directly, I still felt that I didn't live up to her expectation.
A．When
B．Since
C．As
D．While
下列哪些项目可作为诊断慢性肺源性心脏病（肺心病）的条件（）
A.慢性肺、胸疾病史
B.左心室肥大或左心衰竭
C.右心室肥大或右心衰竭
D.肺动脉高压表现
E.双下肢水肿
