If it were not for the fact that she _________ sing, l would invite her to the party.

C . Can't sing （不会，不能唱 /唱的不好）

'she can't sing' 是这句里所说的fact; 事实, 实现在‘发生’的。

答案是C
由于题目上说I should invite her to the party是一般现在时，故选can‘t
该题亦可改为If it were not for the fact that she ___sing，I should have invited her to the party
should have dong表示本应该做某事却未做，此题选A

A

句意是（虚拟语气）：如果不是因为她不会唱歌，我就会请她参加派对

虚拟语气用 couldn't 不是 can't

C 她不会唱歌是不可改变的事实。