sealed copy

基本解释

This class has to be sealed since the build engine instantiates its own copy of this type.
由于生成引擎会实例化自己的这种副本，因此必须密封此类。
Bidder should provide the printed version of various valid qualification certificates, such as business license and operation license, etc (The copy must be signed or sealed by the bidder).
投标人须提供各种（合格有效的）资质证书的复印件：如营业执照、经营许可证等；
A copy of certified transcript in a sealed envelope by the university the applicant graduated from or studied at;
由毕业或肄业之大学密封的学业成绩表一份；