明清北京城是在辽金城垣的基础上改建而成的，共有内外三重城池。( )P47
参考答案：错
—Can she ______ TV now?
—No, she ______. She ______ do her homework first.[ ]
A. watch; can; can
B. watch; can't; must
C. watches; can't; can
D. watches; must; can
出生后到满1周岁之前称为（）
A.胎儿期
B.婴儿期
C.幼儿期
D.学龄前期
E.学龄期
omework first.[ ]