请高手指导一个选择题

选B吧，respectable是修饰人的

选A

这里考的主要是尾缀-ful和-able的区别,-able的意思相当于be capable to do sth,不符合题目的意思。

选择B.

从整个语句来讲，这个句子要表达的意思是他是个品德高尚的绅士。选B，respectable着重讲的是he因为品德高尚而被人所尊重！！
选择A，respectful的话，只是说he很有礼貌，并不致受人所尊重。

因此，选择B，合情合理.

In my opinion, The answer is B.

From cambridge dictionaries, we know that "Respectful" means "showing politeness or honour to someone or someting". For instance: There was a respectful two-minute silence as we remembered the soldiers who had died in the war.

While the meaning of the word "Respectable"is "considered to be socially acceptable because of your good character, appearance or behaviour". For example: a respectable young woman from a good family