Lily and Lucy are twins and Lucy is of the two.A. oldB. oldestC. the oldest D. the elder

问题补充：

Lily and Lucy are twins and Lucy is of the two.

A. old

B. oldest

C. the oldest

D. the elder

答案：

A. old

B. oldest

C. the oldest

(答案→)D. the elder

解析：最高级一般用在三个或三个以上事物进行比较。因为是两个人所以只能用比较级。