All chemicals, including substances like window cleaner or antibacterial cleaner, have the ability to remove the protective coating on the screen, which will inevitably result in a shorter life for your device. Never use a substance other than water to clean the screen.  Don't use cleaners meant for LCD screens, either. Those are meant for a different type of material, and they're harmful to iPhone and iPod Touch screens. Even natural substances like vinegar and lemon juice are too abrasive for cleaning the screen of an iPhone or iPod screen. Water is fine to use in very small amounts, but it should never be directly poured or dripped on the screen. Always use a microfiber cloth to transfer a little moisture to the screen, and make sure to wipe it off right away with a dry cloth.  Submerging an iPhone or iPod Touch in water is a sure way to ruin it. Don't try to soak it in an effort to remove a stubborn stain. If you accidentally get too much water on the screen, examine the user manual that came with your device to determine what steps you can take to fix it. Using an abrasive towel, or even a paper towel or napkin, can scratch and damage the screen of an iPhone or iPod Touch. If you lost the cloth that came with your device, you can pick up a new one at a computer store, or use a cloth meant for cleaning the lenses on glasses. If your device's screen has been damaged by a stain that won't wipe away, check out the warranty that came with it to determine whether you can take it in to have it cleaned or repaired. Trying to do so yourself may result in further damage.

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Write a summary of the previous text in Chinese:
不要使用家用工具来清洁你的 iPhone 或 iPod Touch 屏幕。 不要将设备浸入水中。 使用不起毛的布。 不要拒绝专业设备清洁服务。