She was relieved to see his face light up with a boyish grin.

看到他脸上显出孩子气的笑容，她松了一口气。

《柯林斯英汉双解大词典》

To see their faces light up with joy when you acknowledge one of their ideas.

看到你赞同他们的观点而整个脸都亮起快乐的喜悦。

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To his delight, Nick saw her eyes light up with joy. Then Susan nodded in agreement and responded, "I think it's a great idea!"

让Nick高兴的是，他看到她的眼睛充满快乐。然后Susan点点头表示赞同然后回答说：“我觉得这是一个了不起的注意！”

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What we had just done a clicker question on is discussing light as a particle and the photoelectric effect, so we're going to finish up with a few points about the photoelectric effect today.

我们刚才做得课堂表决器那个问题,是讨论光作为一个粒子以及光电效应，所以今天我们将以一些,关于光电效应的观点作为结束。

麻省理工公开课 - 化学原理课程节选

And if we do, in fact, hit it with light to get the electrons off, it will go back to the straight up in position, or if it gets knocked hard enough it does that, too.

而且如果我们这么做，事实上，用光轰击它以逐出电子，它就会在原位置沿直线返回，或者如果它被撞击的足够猛烈,也会出现上述现象。

麻省理工公开课 - 化学原理课程节选

So what we end up with for the number of photons in this laser beam of light is 2.1 times 10 to the 17 photons.

这个激光束的数目是,2，1乘以10的17次方。

麻省理工公开课 - 化学原理课程节选

Facebook home pages began to light up with questions about what was going on.

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In summer, the headlands light up with pink thrift and plum-coloured heather, attracting rare moths and butterflies.

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Chatboards on ESPN.com still light up with negative comments every time a story about him appears (just scroll down here).

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