would be better 后面怎么跟?改错题：Maybe it would be better choose this house as our meeting room.在choose前加to 为什么 这是什么结构?

没那么复杂，就一句话
be + 形容词 + to do

it 形式主语 ，动词不定式为真正主语。

would be better 表示“.会更好”,往往单独成句,不直接跟动词连用.
如：This car would be better.
也可跟从句,如It would be better that if you can come today.
其他常用句式 This one would be better than that one.
would better + 动词原形与 had better + 动词原形,都表示“最好.”
前者语气上更加委婉一下.
如：You would better go later./ You had better go now.
本题的用法其实是涉及到了 it 引导的形式主语句式.
结构如下：It is +adj.（for sb） to do sth.表示 做.是.（形容词）
如：It is good to read English in the morning.
其中 it 是形式上的主语,代指后面的不定式短语（to do sth）,本身没有意义.
不定式短语（to do sth）是句子的真正的主语,因此可以将此提前.改为：To read English in the morning is good.
本题的形式就是 it would be better （for sb） to do sth
这种句式是为了避免“头重脚轻”,英语的习惯说法,牢牢记住即可.

would be better to do sth
最好做某事
Maybe it would be better to choose this house as our meeting room.
或许选择这间屋子作为会客厅比较好。
这个句子中it 是形式主语，to choose this house as our meeting room整个作为真正的主语，简单的说就是to do 动词不定式作真正主语。