可以，上句可改为：They are so good students. 具体公式如下：so+形容词\副词+名词单复数\主谓结构 例如：They are so beautiful girls. She is so beautiful a girl. So beautifully she\they wear(s)! such+名词单复数+其他 （其中名词单复数结构包括：形容词+名词） 例如：They are such beautiful girls. She is such a beautiful girl. (这两句 (a) beautiful girl(s)就是被视为一整体的名词结构）
不可以。 He is such a good student. 可以讲good 移到前面，用so，变成 ：He is so good a student. 但是这种用法只用于可数名词单数，复数是不可以用的。
第2个回答 2012-10-30
上句可改为：They are so good students. 具体用法如下：so+形容词\副词+名词单复数\主谓结构 he has so good a book that everyone wants to read 可以改写为：He has such a good book that everyone wants to read. We have so much homework to do. 不能够改为such 句式