the mark ( , ) used to separate the items in a list or to show where there is a slight break in a sentence 逗号 The relative clause is separated by commas. 相对子句用逗号分隔。 You need to put a comma before ‘which’. 您需要在“哪个”之前加上逗号。
Word Originlate 16th cent. (originally as a term in rhetoric denoting a group of words shorter than a colon): via Latin from Greek komma ‘piece cut off, short clause’, from koptein ‘cut’.