生理性贫血出现于( )。
A．生后4～6天B．生后3个月C．生后4～6岁D．7岁E．8岁
参考答案：B
解析：[知识点] 小儿血液特点
Look at the naughty boy! You ______ have taught him how to behave himself.
A．must
B．may
C．can
D．should
热网加热器应有哪些装置？
