请问关于不定式 to do 请问是 There are many interesting things to see a

正确的是There are many interesting things to see and do
这里涉及的语法点,是并列不定式省略to的问题.
当两个或多个作用相同的不定式并列时,通常只需在第一个不定式前用to,其余不定式前的to可以省略.如：
He told me to stay there and wait for him. 他叫我在那儿等他.
It is easier to persuade people than (to) force them.说服人容易,强迫人难.
但是,如果两者有对比关系,则后面的不定式前的to不可以省略.如：
To try and fail is better than not to try at all. 尝试而失败总比不尝试好.