例句與造句

1. Pk card is used to realize bi - directional identity authentication of users entry so that it guarantees the legality of users . multi - grade key system , multi - version key and multi - index security system are supported
   采用pk卡實(shí)現(xiàn)用戶登錄的雙向身份認(rèn)證機(jī)制，保證了登錄用戶的合法性。支持多級(jí)的密鑰體系，支持密鑰的多版本和多索引安全體系；
2. It's difficult to find indexed securities in a sentence. 用indexed securities造句挺難的