what a long time he's been waiting,isn't it?

what a long time he's been waiting,isn't it?对吗,为什么 what a long time he's been waiting,isn't it? what a long time we've been waiting,___? It`s the first time that he has been to Australia,isn`t it?中 hello Tom.It's been a long time I haven't see you.I miss you it has been a long time. what is up It ___that he has been ill for a long time It's a long time since还是It has been a long time since 请问He has been waiting for his brother for a long time.是什么时态, 翻译：He has been waiting for his brother for a long time. 请问He's been here for a long time和He's been here a long time的 Hi Mary It's been a long time .语法填空