建筑构图中，关于“对比与微差”的概念，下列哪种说法是错误的()

A．功能和技术必然会赋予建筑以各种形式上的差异性

B．对比与微差是两个相互联系的概念

C．对比与微差是相对的概念

D．对比与微差不局限于同一性质的差异之间

----- As we know, you won’t go back to the USA since you have established a research center here．But how long _____ in America?

----- For almost 10 years．

A．did you study

B．have you studied

C．were you studying

D．have you been studying