第二精馏塔投用步骤。

在办理了税务登记后，从事生产、经营的纳税人的财务、会计制度应当按规定报送主管税务机关()。

A.登记

B.批准

C.备案

D.审核

单词运用。根据短文内容，完成所缺单词。

     A girl came into the office, following the manager. She was so pretty that all the workers stopped to 

(1)l______ carefully at her. Mr. Ball (2)i______ the newcomer to his workmates. The girl asked them

to (3)h______ her. Then she sat down at the desk (4)n______ to Richard. The young mall's heart beat

faster.

     Richard was a leaver (毕业生), too. He (5)l______ a lot when he was at college. He was able and the

manager liked him very much. He was a young mall of few words. So he could say (6)n______ when he

stayed with a girl. He wasn't married though he was nearly thirty. His parents were (7)w______ about it

and they asked their friends to do something for the young man. Of course, the manager purposely (故意

地) put Anne's desk there. Anne had little experience and often asked for Richard's (8)a______. The young

man, of course, (9)t______ his best to help her. And one day he helped the girl solve a (10)p______. She

asked him to have dinner with her the next evening. Richard's parents were all glad. His mother told him

(11)w______ he should say to the girl. She made her son learn them by (12)h______. And when the dinner

was over and Anne was leaving. Richard stood up and stopped her. With a (13)r______ face, the young

mail said what his mother told him. To his (14)s______, the girl refused. "I have a friend and we're going

to (15)m______ this fall," said Anne. "Don't be so sad, my friend. But I still enjoy your good insight (眼光)!"

社会发展同自然界的变化发展一样，也受自身规律的支配，人类社会发展的总趋势并不是由人的主观意志决定的。人类社会发展的总趋势是[ ]

①前进的

②上升的

③曲折的

④前进性和曲折性的统一

A、①②

B、③④

C、①③

D、②④

系统设计的主要活动是( )。

A．系统实施的进度和计划的规定

B．系统设计说明书的编写

C．系统总体结构设计、详细设计

D．上述各项

光纤末端通常有2种情况，即（）和由于末端的不规则性引起的（）。