()标志着产业组织理论体系的初步成熟,产业经济学因此成为一门相对独立的经济学科。
A.有效竞争理论
B.马歇尔冲突
C.SCP范式
D.垄断竞争
参考答案:A
Now many people move into cities in order to have their children___.
A.better educate
B.receive well education
C.better educated
D.accept better education
心内直视手;长时,心内暗红色血液回流异常增多,应考虑存在
A.动脉导管未闭
B.主动脉瓣反流
C.肺静脉畸形引流
D.肺动脉闭锁
E.永存左上腔静脉