在英语语法中，"that"常用于连接两个或多个并列的宾语从句，使句子更清晰、简洁。例如，“I believe that he is honest and that he will do what he promised.” 和 “She said that she would come to the party and that she would bring her friends.” 这样的句子，"that"的使用使得读者更容易理解句子的意思，同时也使句子更流畅，避免了重复的词汇。
- I believe that he is honest and that he will do what he promised.（我相信他是诚实的，他会履行他的承诺。）
这个句子中，that连接了两个并列的宾语从句：he is honest和he will do what he promised。使用that连接宾语从句可以让读者更容易理解句子的意思。
- She said that she would come to the party and that she would bring her friends.（她说她会来参加派对，并会带上她的朋友。）
这个句子中，that同样连接了两个并列的宾语从句：she would come to the party和she would bring her friends。使用that连接宾语从句可以让句子更加流畅，避免了重复的词汇。
除了that之外，还有其他的连接词可以连接并列的宾语从句，比如and和or。但是相较于and和or，that在连接宾语从句时更加常见，更加清晰明了。
