C
Fun作为名词,是不可数名词.因此排除A 和D
还有一句型是 such +形容词+不可数名词+that
so与such都有“如此、这么、那么”的意思,可进行同义改写,但用法不同.
1.so是副词,修饰形容词和副词；而such是形容词,修饰名词.它们后面接单数可数名词时,词序不同.
so的词序为：so+ adj.+ a（an） + n.
such的词序为：such +a（an） +adj.+ n.
它们可以表达同样的意思,因此它们可以进行同义改写.
so nice a coat =such a nice coat 这么漂亮的一件外套
so interesting a book = such an interesting book 那么有趣的一本书
PS：后面接复数名词或不可数名词时,只能用such,而不能用so.如：such beautiful flowers 这么美丽的花 such clever children 如此聪明的孩子
但是,复数名词或不可数名词前有many,few,much,little修饰时,只能用so而不能用such,这是一种固定用法.如：so many books 这么多书 so few people 这么少的人 so much money 那么多的钱 so little milk 那么少的牛奶
2.和“that”连用时,意思基本一样,但句型结构不同.
“so…that…”句型结构为：
so + adj.（adv.） +that…
so + adj.+a（an）+单数n.+that…
so +many（few）+复数n.+that…
so +much（little）+不可数n.+that…
例如：This book is so interesting that I have read it three times.这本书如此有趣,我已经看了三遍.
He spoke so fast that we couldn‘t understand him.他说得太快,我们都未能听懂他的话.
It was so hot a day that nobody wanted to do anything.天气很热,谁都不想干活.
There were so many people that we could hardly move on.这么多人,我们简直无法继续往前走
“such…that…”句型结构为：
such + a （an）+adj.+单数n.+that…
such + adj.+复数n.+that… such +adj.+不可数n.+that…
例如：She is such a pretty girl that everyone likes her.她是个很可爱的小姑娘,大家都喜欢她.
They are such delicious cakes that I want to eat another two.这么可口的蛋糕,我还想再吃两块.
It is such sweet milk that we all want to drink it.这么香的牛奶,我们都想喝.
PS：由于so 和such后跟单数可数名词时,可以换用,同样“so…that…”与“such…that…”也可以进行同义句改写.如上文中：This book is so interesting that I have read it three times.可改写成：This is such an interesting book that I have read it three times.It was so hot a day that nobody wanted to do anything.可改写成：It was such a hot day that nobody wanted to do anything.3.so与that可以直接构成词组“so that”,引导目的和结果状语从句,表示“以便、以致”的意思.如：He worked hard so that he could pass the exams.为了能通过考试,他学习很认真.（但such没有这种用法）