Rectangular cover

A rectangular lid comprising a top surface and a bottom surface, the top surface comprising two opposing short sides and two opposing long sides, where each short side comprises a midpoint, defining the connecting line between the two midpoints as a centerline, the centerline being parallel to the long sides, the centerline being parallel to the long sides. The top surface comprises three sets of strip-shaped protruding structures which are arranged at intervals, the three sets of strip-shaped protruding structures are parallel to the two short edges and intersect with the two long edges, the center point of the three sets of strip-shaped protruding structures divides the center line between the two short edges into four sections, and the length difference of each section is smaller than or equal to 3%. 一种长方形盖子，其包括一顶部表面及一底部表面，所述顶部表面包括两条相对的短边及两条相对的长边，其中，每条短边包括一中点，将两个中点之间的连线定义为中心线，该中心线平行于所述长边，所述顶部表面上包括三组相互间隔的条带状凸起结构，该三组条带状凸起结构平行于两条短边，与两条长边交叉设置，所述三组条带状凸起结构的的中心点将两条短边之间的中心线分为四段，每段的长度相差小于等于3％。