Internet上的服务都是基于一种协议，WWW服务是基于______协议。
A．SMTP
B．TELNET
C．HTTP
D．FTP
参考答案：C
Lucy has ________ all of the goals she set for herself in high school and is ready for new challenges
at university.[ ]
A．acquired
B．finished
C．concluded
D．achieved
窝沟封闭中乳牙的酸蚀时间为（）
A.20s
B.40s
C.10s
D.60s
E.2min
