我们英语老师善于讲有趣的笑话．（be?good?at）___．

答案：Our English teacher is good at telling interesting jokes． 说的是客观事实用一般现在时，主语是our English teacher单数，故be good at（表示擅长…）中的be动词选择is，at是介词，后加动名词短语telling interesting jokes做宾语，tell jokes表示讲笑话，故答案是Our English teacher is good at telling interesting jokes．