New Polo车门采用（）密封工艺，其中车门上拥有两层密封条、侧围上一条，彻底阻隔雨水。
A.一层
B.两层
C.三层
D.四层
参考答案：C
The price system is a complex network _______ the prices of all the products bought and sold in the economy as well as those of a great number of services.
A．consisting of
B．consisted of
C．making up of
D．made up
瘘管的特点是（）
A.多伴有剧痛
B.脓水淋漓不止
C.病理性盲管
D.有内外两口
E.贯通体表与脏腔
