the telephone number several times but he couldn’t learn it by heart.A Having been toldB.

问题补充：

the telephone number several times, but he couldn’t learn it by heart.

A Having been toldB. He had been told . C. Although he had been told. D. Having told

答案：

解析：考查句型结构，根据句中的but可知，but连接的是两个并列句，排除ACD,AD是分词作状语，C是从句从状语

句意为，他被告诉电话号码很多次了，但是他就是记不住。