1. 다음 중 밑줄 친 부분의 쓰임이 보기와 같은 것은?

보기 it was my brother that called me last night.

① it was certain that he would succeed.
② it was yesterday that i met him.
③ it was strange that he got angry.
④ it was true that she would be very busy.
⑤ it is important that you have to have your passport.
it that 강조용법과 가주어,진주어 구별문제인것 같은데,

보기에 나와있는게 강조용법으로 사용된것이 맞는거죠?

강조용법과 가주어,진구어구문을 쉽게 구별하는 방법이 있을까요?

게시판에 구별법에 관한 설명이 나와있어서 읽어보긴 했는데이 문제는 조금 다른것 같아서 질문드립니다!