The road construction is based on the agreement, one of purposes is to ensure its pletion on time.
A. which
B. whose
C. that
D. what
网友回答
A. which
(答案→)B. whose
C. that
D. what
解析：句意：公路的建设是基于协议，其中的一个目的是确保按时完工。这里是非限制性定语从句，先行词是agreement，关系词在从句中作定语，that不能引导非限制性定语从句，what不能引导从句，whose可以在从句中作定语，表示某人的或某物的，故选B。