wholesale prices in july rose more sharply than expected and
wholesale prices in july rose more sharply than expected and at a faster rate than consumer prices,
这句话中at a faster rate than consumer prices 是作什么成分?它的主语是什么?at 开始应该是一个介词短语吧?中间的and是一个连词吗,怎么后一句与前一句关系不太明确呢?有谁能从语法的角度帮我解释一下吗?