用定语从句合并成句子
问题描述：
用定语从句合并成句子
Alex asked the policeman to call him to call him when needing help
the policeman worked with him
the teacher talked about some writers and their books
the writers and their books were unknown to us
he must be from africa
it can be seen from his skin
i can't find the dictionary
the cover of the dictionary is deep red
this kind of trees can be grown in very few areas
there are very few areas in the word
do you remember the day?
you joined our club on that day
答
Alex asked the policeman who worked with him to call him when needing helpthe teacher talked about some writers and their books which were unknown to ushe must be from africa,which can be seen from hi...