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?