







上下摆动 (shàng xià bǎi dòng) means “swing up and down, bob up and down, move up and down, oscillate” in Chinese. See the pinyin, native audio pronunciation, and 2 example sentences with English translations.
swing up and down
bob up and down
move up and down
oscillate
They lay sleeping under a tree, and snored so that the branches waved up and down.
Their wearisome heads went up and down at the same rate, in hot weather and in cold, wet weather and dry, fair weather and foul.