4. He is _____, but he doesn't feel _____. Because he likes to surf the Internet for his study of English.

A．lonely; alone

B．alone; lonely

C．alone; alone

D．lonely; lonely

时间数列发展水平按其在数列中所处位置不同分为（）。

A、中间水平

B、报告期水平

C、基期水平

D、最初水平

E、最末水平