Question

What a lovely day 该怎么回答?

Answer 1

Yes,I like it very much.

What a lovely day! I hope it'll stay fine.

多好的天！我希望能晴下去。

 由"what"引导的感叹句："what"意为"多么"用作定语，修饰名词（被强调部分），单数可数名词前要加不定冠词a/an,复数可数名词或不可数名词前不用冠词。

不定式短语引起的感叹句

不定式短语单独使用常表示惊异、气愤、祝愿等情绪。

To sell such a cheap suit as that to a millionaire 竟然把这样一套衣服卖给一位百万富翁！

To think that I shall never see her again!真没想到我再也见不到她了！

To think of my leaving the umbrella in the train! 真没想到我把伞落到火车上了！

Answer 2

Yes,I like it very much.
Certainly,good day for picnicking.
What a lovely day 本身就是一句客套话,西方人见面不是问“吃过了么”这种中国式客套话,大多是随便聊天气.回答方式只要随着天气随便说点就行.