As you stand, maintain the natural curve in your lower back and keep your core muscles tight.

在你站起来的时候，继续保持腰背部的自然曲线，保持收紧你的核心肌肉。

youdao

As you stand, maintain the natural curve in your lower back and keep your core muscles tight. Use your leg muscles - not your back - to lift the object.

在你站起来的时候，继续保持腰背部的自然曲线，保持收紧你的核心肌肉。用你的腿部肌肉——不是背部——去抬起物品。

youdao

Maintain the natural curve in your lower back, and keep your core muscles tight.

保持腰背部的自然弯曲，保持收紧你的核心肌肉。

youdao

There are a couple of corners that can be fun but the majority are difficult, tight and there isn't any natural flow to the track.

CNN: Lorenzo welcomes MotoGP rival Rossi back to Yamaha

Fracking is a vital contributor to the recent renaissance in the U.S. oil and natural gas supply picture, as it is the technology, along with horizontal drilling, that makes producing oil and natural gas from very tight shale rock formations possible.

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