求教英语单选__several times,but he still doesn't know how to do it

___ several times,but he still doesn't know how to use the c having been told mang times ,he still didn't know how to do Having been told many times,he still didn’t know how to do i That you don't know how to do it doesn't bother me,but you t 语法 ___several times,but the boy doesn't know how to answer t he doesn't know how to do next（改错） He doesn't know ---A what to do B how to do 选那个,为什么, _many times,the boy still didn't know how to do the exercise "but how can you?you don't know how to write!" "it doesn't m 1.___many times,but he still couldn't understand it. _____scores of times,but he still couldn't understand it. ____ many times but he still couldn't understand it