The place the bridge is supposed to be built should be the cross river traffic is the heaviest.
A. which; where
B. at which; which
C. at which; where
D. which; in which
网友回答
A. which; where
B. at which; which
(答案→)C. at which; where
D. which; in which
解析： The place是先行词，在定从 the bridge is supposed to be built中在地点状语，用at which或where；should be后面是表语从句 the cross river traffic is the heaviest.，该从句缺少地点状语，用where引导。所以选C。