腰椎间盘突出症和梨状肌综合征相似的症状体征是

A．臀部和下肢痛

B．直腿抬高试验阳性

C．神经定位征明确

D．髋外展外旋抗阻力时可诱发神经痛症状

E．臀部压痛

In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet. There are two types of key technology: private key and public key. Private-key encryption methods are called (71) ciphers, information is encrypted with (72) both the sender and receiver hold privately. Public-key encryption methods are called (73) ciphers, (74) created for each user, encryption key and decryption key are (75)

A．a key

B．two keys

C．three keys

D．four keys