77："I know that that is true" 是正确的吗？

QUESTION 77: Is it correct to say "I know that that is true"?

ANSWER: It's correct. The first "that" is an indicator of object clause and can be omitted. The second "that" is a pronoun.

问题77："I know that that is true" 是正确的吗？

回答：正确。第一个"that" 是宾语从句的连接词，可省略。第二个"that"是一个代词。