12. If our national economy develops at the same speed ____for the past decade, we are sure we can catch up with the advanced countries in the world in 50 years.
A. as it was
B. as it did
C. as it does
D. as it has done
(责任编辑：admin)要这答案加QQ：800020900 或加微信：vq800020900 获取
