how fun it is to do可用么（fun做adj)

how fun it is to do可用么（fun做adj) 为什么能说What fun it is to do sth.却不能说How fun it is to do sth. It is fun to do sth.句型fun的词性 how fun it is to do … what fun it is to do… 为什么要用后者,fun如果当形容 it's fun doing中的fun 是adj it's fun to do 是n .这种说法对吗? it's fun to do 换成 感叹句是what fun 还是 how fun 英语中的“fun”今天我们做了一张04年期终模拟卷,出现了这样一道题：How ___ （fun）it is to do it is fun to do 还是 doing? It is fun to do sth造句 It is great fun to do ... It is fun to do sth.造句. It is fun?到底是It is fun to do sth 还是It is fun doing sth?It is