高手来指点一下谢谢~！！！

一般是such a(n) .......比如It was such an exciting game.其实是一种感叹的语气。参考：

The firm couldn't afford such a high salary standard.

因为salaries是复数，就不能用a了。

不可以，一因为salaries 是复数形式。
可以说： such a large salary
so large a salary

no.

The firm couldn't pay such a large salary.

复数形式：
The firm couldn't pay such large salaries.

a such ... salaries数上不一致。

不可以，such 不能用来修饰large,而要用so

不可以，salaries是复数，不能用表示单数的a