While he was not dumber than an ox, he was not any smarter; so most of his classmates were lenient and helped him along.
【正确答案】
B
【答案解析】本句的后半句说的是他的很多同学都是友爱无私的，他们帮助他共同前进。lenient在句中的意思是“仁慈的，宽大的”。helpful“有帮助的，有益的”，enthusiastic“热心的，热情的”，intelligent“聪明的”都不符合句意。merciful“仁慈的，慈悲的”与题中词意思接近，如：The merciful king saved the two young officers from death．(仁慈的国王把两个年轻的军官从死神手中救了出来。)