fluctuate

波动，使波动英释vvto change frequently in size, amount, quality, etc., especially from one extreme to another

With prices ______ so much, it is difficult for the school to plan a budget.句意： 物价起伏这么大， 学校很难制订预算。vibrate： (使)振动； flutter： 拍翅； 飘动； swing： 摇摆。214swinging

1 Insect populations fluctuate wildly from year to year..昆虫的数量每年变化很大。

2 Prices were volatile, fluctuating between 20 and 40..价格不稳定，在20至40美元之间波动。