逗号后是一个名词词组,并不是句子,所以不需要连词。that是关系代词引导定语从句,并在从句中作主语,修饰a disappointing holiday season performance。这个名词词组是前面句子的句子同位语。如果在这个名词词组前加上which was,就成了which引导非限制性定语从句了,which的先行词为前面主句的内容。 stores open more than a year 应该为 stores that have been open for more than a year 或者 opened more than a year before.