“If the fiber cell walls are extremely thick and heavily lignified, as in wood of oak or hickory, it may take a great deal of force to flex the wood.”

“I stand on my tip-toes and flex every muscle in my body that I can.”

“He flexed his ankle, silently thanking God that it had held out thus far in the evening.”

“Kel gingerly flexed the fingers of her right hand while her mind raced for an answer.”

“The air flexed outwards from the tip of the staff, stealing the breath from the room.”