试题题干
（）all his children come to his birthday party, the old man would be much happier.
参考答案
正确答案：
试题解析
本题考查虚拟语气。If all his children should come to his birthday party…,当省略if的时候，要把主语all his children后面的词提前，因此变为should all his children......句意：如果他所有的孩子都来他的生日派对，老人会更加开心。