It's a lovely baby的it是什么意思,为什么要这样用?

It's a baby kangaroo,it's lovely中文? is't it a lovely weather为什么要用a 有类似于这样的句型吗?It's a lovely day ,isn't it? Yes,isn't it. It's a baby bear的中文 It's going to be a lovely day .为什么用 be怎么解释 求It's a Lovely Day Tomorrow 的歌词 It S A Lovely Day 歌词 it's a lovely day改为感叹句 It's A Lovely Day 歌词 It's,lovely. it's lovely what b___ sunshine it is it's a lovely day