It'd fog up their telescopes.

这会让他们的望远镜蒙上一层雾气。

youdao

Sometimes the nose fit isn't perfect and my eyeglasses fog up.

有时候鼻子部分不是很贴合，我的眼镜就起雾了。

youdao

Fog up a piece of glass with your breath and look through the fogged plate in a darkened room at a white-light point source.

哈气使一片玻璃蒙上一层水雾，并在一个暗间里通过它来观察一个白色点光源。

youdao

She could see the lake. Some fog was coming up as the sky darkened on this Halloween night.

VOA: special.2010.10.30

Until then the West should export large quantities of desiccants and plastic storage bags to help at least cut some of the humidity, which can fog up mirrors and worse.

CNN: ASIANOW - TIME Asia | Asia Buzz: Tattle in Seattle

The morning started out quite grey and overcast, but as the clouds started to break, the sun came out and a fog rose up.

BBC: Meet this month��s BBC Travel Photo Nomad

The first time we go to Sea Cliff, where Alice lives, she points up a hill at fog sneaking through the eucalyptus trees and says that her old school is up there: an all-girls school that her little sisters go to now.

NEWYORKER: Ask Me If I Care