The wood is held in position by a clamp . 木头用钳夹固定住了。
2.
The trunnion assembly is supported by air bearings at the end of each arm and is held in position by brake shoes at each bearings . 耳轴组件的支承是每根臂末端的空气轴承，轴承上的闸瓦起定位作用。
3.
Solids have definite shapes ( e . g . crystals ) . the particles are held in position . they just vibrate 固体有明确的外形（如晶体） 。粒子固定在某个位置，它们只是在振动。
