点击下方单词,选择对的这个单词
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名词
1. 堡垒;防御阵地;要塞A fortress is a castle or other large strong building, or a well-protected place, which is intended to be difficult for enemies to enter.
1. a fortified defensive structure
Synonym: fort
多通过句子记忆单词，而不是单独死记硬背。
