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 :

 다음을 읽고 물음에 답하시오.
John was driving home late one night when he picked up a hitchhiker. As they drove along, he became (가)[conscious/suspicious] of his passenger. So John checked to see (a)[that/if] his wallet was (b)[safe/safely] in his coat that was on the seat (c)[among / between] them, but it wasn’t there! Immediately, he stepped on the brakes, ordered him out, and said, “Hand over the wallet right now!” (d)Frightening, he handed over a wallet and got out of the car. When he arrived home, he started to tell his wife about the experience. She (나)[interrupted/protected] him, saying “Before I (다)[remember/forget], John, do you know (e)[that/what] you left your wallet at home this morning?” 빨간글씨 that과 if 구별이 쉽지않네요.맨 마지막도.that과 what,.해석상 둘다 되는것 같은데 정확이 that의 쓰임이 뭐였고 왜 안되는지 알려주시면 감사하겠습니다.