_____ is this letter from?(who) 怎么写?请说明原因

who is this letter from?who 什么成分? This is _____（definite) a letter from your pen-friend who is the letter from who is the letter from? This letter is from ___ ：---Who is _____?---This is Jack from Britain.A this B that letter is this grandma from your a ) this letter is from my pen p___ we don't have a clue who did this中的who did this 是什么从句 请说明原因 what is mum going to cook tonight?怎么回答?who weote this letter Can you _____ this letter from German ____ English? Who is this toy car from?