Sandcastles crumbled under the waves' attack.
Meaning: This means the sandcastles were destroyed by the waves that kept hitting them.
Choice of Words: Sandcastles are structures made of sand, often built by children on beaches. Crumbled means to break into small pieces. Under means in a lower position or place than something else. Waves are large bodies of water that move across the sea. Attack means an attempt to harm or defeat someone or something.
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