金某于2000年取得县工商局颁发的营业执照，经营期为10年。2001年年检时，县工商局将经营期限改为5年，金某不服。他的下列做法正确的是( )。

A．可在2个月内向县人民政府提起行政复议

B．可在2个月内向县人民法院提起行政诉讼

C．可在2个月内向市工商局提起行政申诉

D．可在2个月内向市工商局提起行政复议

In a public-key cryptosystem, (71) encrypted with the public key can only be deciphered with the private key from the same (72) . Conversely, (71) encrypted with the private key can be decrypted only with the public key. Users can make their public keys (73) available or place them at a key distribution center or others to access. However, the private key must be (74) safe. In public-key systems there’s no (75) to find a safe channel for communicating a shared secret key.

（75）是（）

A.more

B.necessary

C.need

D.space