Get a clean microfiber cloth damp by placing it under lukewarm water. Squeeze out excess moisture so water does not drip from the cloth. Use the cloth to wipe off any debris, then allow the glass to dry. Metal polish is good for gently sanding large, delicate surfaces such as windshields. Choose a cloth that won’t leave threads on the glass. A cotton ball works well as an alternative. Dip the cloth in or squeeze out the polish so the cloth over your finger receives a small amount of the polish. Limit the amount of polish you use, since overworking the glass with the polish can lead to additional scratches. The kind of polish that works quickest has cerium oxide in the ingredients. Jeweler's rouge is a more expensive polish option. Place the cloth and polish on the scratch.. Move the cloth with circular motions for about 30 seconds. The scratch should lessen or disappear entirely. Don’t add more polish, since this is likely to damage the glass. Use a clean cloth and dampen it in lukewarm water. Wipe it over the polished area to remove the metal polish.

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Write a summary of the previous text in Vietnamese:
Lau sạch kính. Quấn mảnh vải quanh ngón tay. Nặn kem đánh bóng lên mảnh vải. Chà kem đánh bóng lên vết xước. Lau sạch kem đánh bóng.