You've got that facial expression down.

你记住了那个面部表情。

youdao

The rates of COMT gene expression down-regulation in OCD patients with OCPD and ones without OCPD were 14%and 56%respectively.

伴强迫人格与无强迫人格的强迫症患者COMT基因表达水平分别下调14%和56%；

youdao

She glared down at me with a peevish expression on her face.

她低头瞪着我，一脸怒气。

《柯林斯英汉双解大词典》

Americans use another expression that is similar in some ways to down to earth.

VOA: special.2009.03.08

But you can write it down It's a concept that links itself to a literary or verbal written expression.

但是你们可以将负二的平方用笔写下来,那是种概念，能将其自身,与文学或文字书面的表达连接起来。

麻省理工公开课 - 电影哲学课程节选

Another expression linked to sailing is batten down the hatches.

VOA: special.2009.05.24

And remember that old expression: what goes up must come down?

FORBES: By Keeping PCs, Is HP Betting that Tablets are Disruptive - or Not?

And if you sit down and - I mean I use the expression reading carnivorously...

NPR: Could You Be the Great American Novelist?

Hunters also can choose a facial expression and opt for a paws-up or paws-down pose.

WSJ: After Long Hibernation, Taxidermists Make a Killing During Bear Season