在Internet中,邮件服务器间传递邮件使用的协议是______。
参考答案:SMTP或简单邮件传输协议
解析: 在Internet中,SMTP负责在邮件服务器间传递邮件。
— Liu Fang, I didn't know you can play the Pipa and Guzheng so well.
— Well, actually I ________ it since I was six years old. [ ]
A. plays
B. have been playing
C. played
D. had been playing
引起1型糖尿病的诱因
A.肥胖
B.缺乏体力活动
C.多次妊娠
D.腮腺病毒感染
E.精神刺激