作模型厚薄要求，一般腭顶和口底的最薄处应保持
A．1～2mm
B．3～5mm
C．6～7mm
D．8～9mm
E．10～12mm
参考答案：B
You look smart in this new jacket. That old one ______ thrown away many years ago.
A．ought to be
B．ought to have been
C．would be
D．would have been
《本草纲目拾遗》的作者是（）
A．陶弘景
B．赵学敏
C．李时珍
D．唐慎微
E．苏敬
