When not in use, the fins are tucked into special grooves or depressions so that they lie flush with the body and do not break up its smooth contours.

当鱼不使用鱼鳍时，会将它们折叠起来，收回到特殊的沟槽或者凹陷部位；这样鱼鳍就可以与身体保持齐平，以维持它们平滑的外形。

youdao

They ghosted up the smooth waters of the river.

他们无声地航行在平静的河水上。

《牛津词典》

The boys threw their hockey gear to the top of the hill and tried climbing up the path, but the sleet had created a smooth glacier.

男孩儿把他们的冰球装备扔到山顶上，然后试着沿小路往上爬，但雨夹雪已经令山坡变得更加的滑。

youdao

His form is made up of smooth lines and geometric forms.

VOA: special.2010.08.04

thirty-six feet per second up. Very smooth, very quiet ride."

VOA: special.2009.07.15

During that time, while on tour in Europe and Southeast Asia, he decided to stray from his usual regimen of smooth jazz and focus on the jazz classics he heard growing up.

VOA: standard.2010.04.12

Their momentum took them to the curved bottom, then back up along the smooth walls, allowing them to spring up, two feet in the air.

WSJ: Tim Payne, the Architect of Awesome Ripping | Creating

Even more troublesome, those smooth curves going up, then down, turn out to be misleading.

ECONOMIST: Local difficulties

So the more the Obama administration team can work on the process and interact with the other participants, the easier it will be ensure a smooth follow-up to that meeting.

NPR: Can The Global Crisis Wait For A New President?