fluctuate
/ˈflʌktʃueɪt; `flʌktʃʊˌet/ v[I, Ipr]
~ (between A and B)
1 (of a price, number, rate, etc) rise and fall; change irregularly （指价格、 数量、 比率、 费用等）涨落, 波动
The price fluctuates between 5 and 6. 价格在5英镑与6英镑之间波动.
2 (of an attitude or a state) change continually and irregularly; waver （指态度或状态）变化不定, 动摇
fluctuating opinions 变化不定的意见.