253. Analysts blamed May's sluggish retail sales on unexciting merchandise as well as the weather,which was colder and wetter than usual in some regions, slowing sales of barbecue grills and lawn furniture. 在此slowing是否是现在分词作后置定语,修饰sluggish retial sales?根据主谓一致,不可能是做伴随壮语的。