nuclear envelope

例句：

1. 1. The cell's nucleus is enclosed by a nuclear envelope.
   细胞的核被一个核膜包围。
2. 2.The study of the nuclear envelope has revealed new insights into gene expression.
   对核膜的研究揭示了基因表达的新见解。
3. 3.The scientists found that the nuclear envelope plays a crucial role in DNA replication.
   科学家们发现，核膜在DNA复制中起着至关重要的作用。