Avoid laser pointers (that red dot moving all over the place will give you away) and while it's okay to speak from notes, don't use loose paper, which "will flap like a sail."

千万不要拿激光教鞭（那个红点四处乱窜，会让你的紧张显露无疑）。在演讲时参考笔记是可行的，但不要使用松软的纸张，因为它们会“像船帆一样来回摆动。”

youdao

People who target aircraft with laser pointers will be treated "extremely seriously", police have warned.

BBC: Green laser

Commercially obtained laser pointers project just a tiny beam, but its diameter grows much bigger as the distance increases and can result in temporarily blindness if shone in someone's eyes.

BBC: Man gets 30 months in prison for shining laser at plane

These range from microwave ovens and laser light shows to home security systems and medical imaging devices. (CDER even regulates laser pointers but not online presentation software, if ever a true risk to human health).

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