A great deal of advanced science and technology has been since China carried out the reform and opening policy.
A. brought down
B. brought in
C. brought out
D. brought up
网友回答
A. brought down
(答案→)B. brought in
C. brought out
D. brought up
解析： 考查短语辨析，brought down 降低，brought in引入，brought out产生，brought up提出，句意：自从中国执行改革开放以来，许多先进的科学技术已经被引入了。故选B。