geom_rect(aes(xmin=23,xmax=28,ymin=-Inf,ymax=Inf),
fill="grey",alpha=0.3)+
geom_rect(aes...xmax=28,ymin=-Inf,ymax=Inf),
fill="grey",alpha=0.3)+
geom_rect(aes(xmin=35,xmax=52,ymin...xmax=28,ymin=-Inf,ymax=Inf),
fill="grey",alpha=0.3)+
geom_rect(aes(xmin=35,xmax=52,ymin...xmax=28,ymin=-Inf,ymax=Inf),
fill="grey",alpha=0.3)+
geom_rect(aes(xmin=35,xmax=52,ymin...五个颜色和透明度都是设置一样的,最后效果看起来 为 啥差别这么大呢?