However, surface B has the same problem after several drop tests that the reverse side of the lid is cracked and there are visible cracks but no cracking in the surface .

• 面反复经过几次跌落测试都是发生同样的问题；盖子的反面都会有裂痕；而盖子的正表面可以看到有明显的凹陷；但是没有开裂.