One button will be at the top of the collar. The other will be partway down it. Each button should have two holes with thread passing up and down through them, not side to side. The buttons should not appear crooked. The threading should appear to hold them tightly in place. Mother of pearl buttons are all unique. You may notice a rainbow shimmer from a distance. When you look close, you should notice that each button has its own pattern. They may also have some marbling on the back. Plastic buttons are mass-produced and look identical. Real Lacoste polos have mother of pearl buttons instead of plastic ones. Plastic buttons feel softer and warmer but with hard edges. They’ll also lack the dip in the center that real Lacoste buttons have. If you still aren’t sure, try tapping the buttons against your teeth or biting down on them. Mother of pearl buttons should feel harder and denser than plastic buttons. 2017 Lacoste shirts now may have this print on the buttons depending on the style). Buttons on authentic Lacoste polos do not have the brand name printed on them. Letters on the buttons is a sure sign that the buttons are plastic and fake.

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Write a summary of the previous text in Chinese:
检查两个纽扣是不是竖着缝在衣服上的。 检查纽扣是否都一样。 摸一摸纽扣，看它们是不是贝母做的。 如果纽扣上印有Lacoste字样，那就更不能买了。