there is （ ）“h”in the world “chair”字母前边用什么定冠词

there is （ ）“h”in the world “hour” 哪些单独字母前面加an,比如例题：There is an “h” and a“u” in the world "hous chair,the,is,a,in,there,corner Is there a chair in the room? there is h in the world hour,and h is the first letter of ho How many chair are there in the room?There is a chair in the 用there is /there aer /have/ has填空.__a chair in the room. Thene is （）“h”in the world "have" there is nothing in the room ---------- a chair 1.there is nothing --- a chair in the room. there is always___ something in the world 什么字母前面要用an经常碰到这样子的题目There is _____"h"in the word ‘hour’A/ B