undulation
US /ˌʌn.djʊˈleɪ.ʃən/
UK /ˌʌn.djʊˈleɪ.ʃən/
名词
波动
a continuous up and down shape or movement, like waves on the sea:
示例:
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The fields rise and fall in gentle undulations.
波动
a continuous up and down shape or movement, like waves on the sea: