Prices at the producer level are only 1.3 percent higher now than a year ago. 这里价格的比较为什么是错的?我觉得是now和a year ago比较。正确答案是Prices at the producer level are only 1.3 percent higher now than those of a year ago,但than后面是一个具体的prices,than前面的now是修饰are,没有一个具体的价格和它平行。想不明白