名词短语
中文翻译：永久锁住的信封
同义词：
['permanently sealed envelope', 'permanently sealed letter', 'permanent sealed envelope例句：1. The package was delivered to the address on the label', 'but it was a permanenly locked envelope.（包裹被送到了标签上写的地址，但它是一个永久锁住的信封。）']
例句：
-
1. The package was delivered to the address on the label, but it was a permanenly locked envelope.
包裹被送到了标签上写的地址，但它是一个永久锁住的信封。
-
2. She carefully opened the envelope and found a letter inside.
她小心翼翼地打开了信封，里面发现了一封信。
-
3. The sender had written a message in the envelope, which she couldn't open without a key.
发件人在信封里写了一条信息，她没有钥匙就无法打开。