南方的丝织业胜过北方是在[ ]
A．唐朝
B．五代
C．北宋
D．南宋
答案：C
I demanded that he _____ English to help him improve it gradually.
A．practise reading
B．practised reading
C．could practise reading
D．would practise reading
胎儿腹围测量一般用于孕几周，可以补充胎儿双顶径估侧胎龄的不足
A．9～12周B．16～20周C．28～32周D．36～42周E．20～28周
