患者，男，42岁，入睡打鼾伴憋气15年，白天嗜睡，精神疲劳，记忆力下降。身高165cm，体重95kg。高血压病史3年，血压145/95mmHg。

悬雍垂腭咽成形术治疗OSAHS，可能出现的术后并发症有（）

A.鼻咽反流

B.鼻咽狭窄

C.开放性鼻音

D.术后出血

E.呼吸困难

F.咽部异物感

G.味觉改变

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.

A. length B. pair C. sizeD. space