一般婴儿添加辅食的时间是()
A.出生后4~6个月
B.出生后3~4个月
C.出生6个月以后
D.只要母乳不足,随时可以添加
E.以上都不对
参考答案:A
圆和圆环都是轴对称图形都有无数条对称轴.______.
William found it increasingly difficult to read,for his eyesight was beginning to . [ ]
A. disappear
B. fall
C. fail
D. damage