답변을 얻은 뒤 반드시 감사의 덧글을 남기고, 좋은 답변은 채택해 주시는 센스...
질문할 때 예의를 지키시기 바랍니다.(빨리... 고수분만..... 이런 식의 요구는 자제 바랍니다.)
질문 내용 :

1. 다음 글의 밑줄 친 부분 중, 어법상 틀린 것은?
After moving to a new city, I ①joined the company baseball team. Being the oldest player, I had to play the outfield. During one game, I made a ②few mistakes. Then I kept ③hearing someone shouting, “Way to go, Mr. Green” and “You can do it, Mr. Green.” I was amazed someone would know my name in this strange city. After the game, I met my wife and son and asked ④that they knew who was shouting encouragement in the stand. My son spoke up and said, “Dad, it was me.” I asked why he was calling me Mr. Green and he replied, “I didn’t want anyone ⑤to know that I’m your son.”

여기서 ④that이 정답인데 왜 정답인지 모르겠어요ㅡㅜ. 다른번호는 이해를 했거든요.
④번만 좀 설명 부탁할께요ㅠ