stretching and flexing manipulation

例句：

1. 1.The scientist used a new technique to stretch and flex the material.
   科学家使用一种新的技术来拉伸和弯曲材料。
2. 2. The engineer had to manipulate the machine to achieve the desired results.
   工程师不得不操纵机器以达到期望的结果。
3. 3. The dancers performed a stretching and flexing sequence to showcase their flexibility.
   舞者们表演了一段伸展和弯曲的序列，以展示他们的灵活性。