Question

___many times,tom stilldid not know what i meant then ___many times,he finally understood it

A.told B having been told 讲一下区别 第一个选A第二个选B
从then为句末词。后面是另一个句子

Answer 1

这里B是独立主格结构，省略主语但要有主语的，而主语就是Tom，是tom被告诉因此要用被动语态，只能选B，逗号前面构成分词结构。这种表达只有ing和being done两种不可以用A哦 否则就得说 Tom has been told many times,and he still........了
你把 空到times括起来 就可以看出其实也是充当分词状语， 因此还要选B
Having been told many times, Tom still did not know what I mean then (having been told many times) he finally understood it.