The sweater is than that one.A much more cheap B much cheap C much cheaper

问题补充：

The sweater is than that one.

A、much more cheap B、much cheap C、much cheaper

答案：

解析：句意：这件毛衣比那件要便宜得多。通过句意than，可知用比较级，cheap的比较级为cheaper，比较级前面用副词much修饰，表程度， much cheaper便宜得多。