两个或两个以上的人以口头语言为工具，以对话为基本形式，面对面（或通过声频电子通讯器材

儿童上前牙牙折最常发生于（）

A.伴有上颌后缩

B.伴有Ⅰ类错

C.伴有Ⅱ类1分类错

D.伴有Ⅱ类2分类错

E.伴有Ⅲ类错

功能性电刺激疗法是应用下列哪一种频率的电流（）。

A.直流电

B.低频电流

C.中频电流

D.高频电流

E.以上均不是

______是指受要约人同意要约的意思表示。

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．two related keys are

B．a key is

C．two unrelated keys are

D．three keys are

野驴妊娠的产前征兆及产后养护有哪些？