start doing的造句是什么?带中文!

英语 It'll start raining in the afternoon 用start doing 这个形式吗?
一下是我对start/begin 知识点收集.
begin / start to do sth
begin / start doing sth.
1） 谈及一项长期活动或开始一种习惯时,使用doing.例如：
How old were you when you first started playing the piano?你几岁时开始弹钢琴?
2） begin,start用进行时时,后面动词用不定式to do.例如：
I was beginning to get angry.我开始生起气来.
3）当后面的非谓语动词指心理状态或精神活动（即表示想法、
意见等的词,如think,realize,wonder,understand等）时
I begin to understand the truth.我开始明白真相.
She started to wonder who had done it.她开始想是谁做了这件事.
4） 事物作主语时.例如：
The snow began to melt.雪开始融化了
It'll start raining in the afternoon .这句话是教科书里面的.