I shall pen down what I know about the subject.

我将笔下来我知道这个问题。

youdao

Press and hold your pen down on the image of the light bulb.

在电灯泡的图像上按下并保持您的笔。

youdao

I take the smallest possible knapsack, containing a map, a notebook, money, a pen, a pencil in case the pen lets me down, plasters for blisters, my door-keys.

我带上尽可能小的背包，包括一张地图、一个笔记本、钱、一支钢笔、一支铅笔以防钢笔让我失望，还有水疱的药膏、我的门钥匙。

youdao

"I now lift this pen to sign this Americans with Act and say let the shameful wall of exclusion finally come tumbling down."

VOA: special.2010.07.28

That's four items. Show up, sit down, and the first question is does anybody have a pen?

总共4件东西，你们来到，坐下，第一个问题是你们有带铅笔吗？

麻省理工公开课 - 固态化学导论课程节选

Now, if you guys are using your computer or you have a pen, I'd just like you to write down what your estimates are of a few foods I'll show you and see what you say.

使用你们的电脑,或者拿起支笔,请写下对以下我展示的一些食物,卡路里的估测,让我们看看结果

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

When she put her pen down, there was not a copy left to sign.

ECONOMIST: America rediscovers its heartland

The pen may be mightier than the sword, but Mighty cuts the ordinary pen down to size as well.

FORBES: Adobe Rethinks The Power Of The Pen With Project Mighty

Until I read one news headlines that had me put my pen down, and think again about this one topic.

FORBES: Connect