that과which은주로혼합해서쓰이는데요that의용법이까다로움안쓸곳은점과전치사뒤에는쓸수가없고쓰여야할것은선행사에최상급,서수표현,only,same,as의문문등 ^^
당신은 어느 그룹입니까?