These are long metal or fiberglass arms (sort of small versions of the cranes you see on building sites) which allow the camera to be lifted up to great height and down again.

• 这些是长金属或玻璃纤维长臂（就是小型的建筑工地上用的塔吊），它可以吊着摄影机升高到很高的位子然后再降下来。