单选题 It has been suggested that we should adopt a flexible retirement age system, those with better health work longer for a bigger pension, those with poor health work for a shorter period of time but at a certain cost.

A、 fragment
B、 choppy
C、 comma splice
D、 correct

【正确答案】 C

【答案解析】解析：【改正】…，making those with better health work longer for a bigger pension，as well as those… 因为两个逗号后内容与前面的内容间没有连词，所以是逗号叠加句错误。首先，两个those…间为并列关系，故连词用as well as，也可以用and。It has been…system与后面的两个those…间为从属关系，可以把第一个逗号改成“逗号+making”或“逗号+which make”。