flexing

基本解释

She had to concentrate on flexing her pectoral muscle, or the triceps, to power the arm.
爲了給手臂提供力量，她不得不用力伸縮她的胸肌或者三頭肌。
In itself, this was just an example of the Big Unfriendly Giant flexing its muscles, but it could be a harbinger of things to come.
例子本身衹是說明這位不友善的巨人是如何展示他的肌肉的，但它也許可以被看作一個預兆。
The British man has a robotic arm, which he controls by flexing muscles in his shoulders.
這名英國人有支機械手臂，他通過收縮肩膀的肌肉來控制這支手臂。

The Taliban was founded outside the city in 1994, and have recently been flexing their muscles again.

Hezbollah has tightened its grip on southern Lebanon, and is flexing its muscles in Beirut.
NPR: Transcript: Obama's Speech at AIPAC
China has complained loudly about America's recent muscle-flexing, particularly its joint military exercises with South Korea.
ECONOMIST: What lies behind the Dear Leader’s latest trip to China?
And now the group is flexing its muscle in politics and especially in the courts.
NPR: Conservative Christianity and America's Culture Wars

If you flex your muscles or parts of your body, you bend, move, or stretch them for a short time in order to exercise them.
A flex is an electric cable containing two or more wires that is connected to an electrical appliance.
to flex your muscles&rarrsee muscle