very carefully locked and guarded
Ví dụ:
- a high-security prison
kept in a prison that is very carefully locked and guarded
an ninh cao
/ˌhaɪ sɪˈkjʊərəti//ˌhaɪ sɪˈkjʊrəti/very carefully locked and guarded
kept in a prison that is very carefully locked and guarded