一钢筋混凝土管，污水管D=700mm，壁厚80mm，覆土深度1.5m，则管道深度为

机器是构件之间具有确定的（）运动、并能完成有用的机械功或实现能量转换的构件的组合。

以被收购企业资产和将来的收益能力做抵押，从银行筹集部分资金用于收购行为的筹资活动通常被称为（）。

A．商业信用筹资 

B．发行债券筹资 

C．短期借款筹资 

D．杠杆收购筹资

When Scotsman Alexander Graham Bell invented the telephone in 1876, it was a revolution in communication. For the first time, people could talk to each other over great distances almost as clearly as if they were in the same room. Nowadays, though, we increasingly use Bell’s invention for taking photographs, accessing the internet, or watching video clips, rather than talking. Over the last two decades a new means of spoken communication has appeared: the mobile phone.

The first real mobile telephone call was made in 1973 by Dr Martin Cooper, the scientist who invented the modem mobile handset（手机）. Within a decade, mobile phones became available to the public. The streets of modem cities began to feature sharp-suited characters shouting into giant plastic bricks. In Britain the mobile phone quickly became the same with the “yuppie”, the new type of young urban professionals who carried the expensive handsets as status symbols. Around this time many of us said that we would never own a mobile phone.

But in the mid-90s, something happened. Cheaper handsets and cheaper calling rates meant that, almost overnight, it seemed that everyone had a mobile phone. And the giant plastic bricks of the 80s had changed into smooth little objects that fitted nicely into pockets and bags.

Moreover, people’s timekeeping changed. Younger readers will be amazed to know that, not long ago, people made spoken arrangements to meet at a certain place at a certain time. But later Meeting time became approximate under the new order of communication: the Short Message Service （SMS） or text message. Going to be late? Send a text message! It takes much less effort than arriving on time, and it’s much less awkward than explaining your lateness face to face and the text message has changed the way we write in English. Traditional rules of grammar and spelling are much less important when you’re sitting on the bus, hurriedly typing “Will B 15mm late - C U @ the bar. Sorry! -).”

Alexander Graham Bell would be amazed if he could see how far the science of telephony has progressed in less than 150 years. If he were around today, he might say “That’s gr8! But I’m v busy rite now. Will call U 2nite.”

小题1:What does the underlined part in Para.2 refer to?

A．Houses of modern cities.

B．Sharp-suited characters.

C．New type of professionals.

D．Mobile phones.小题2:According to Paragraph 4, why did Meeting time become approximate?

A．People were more likely to be late for their meeting.

B．SMS made it easier to inform each other.

C．Young people don’t like unchanging things.

D．Traditional customs were dying out.小题3:If you want to meet your friend at the school gate this evening, which of the following message can you send him?

A．Call U@ SKUg8 2nite.

B．IM2BZ2CU 2nite.

C．CU@ the bar g8 2nite.

D．W84U@ SKUg8 2nite.小题4:What does the passage mainly tell us about?

A．Alexander Graham’s invention.

B．SMS as a new way of communication.

C．New functions of the mobile telephone.

D．The development of the mobile phone.

某羧酸酯的分子式为C18H26O5，1mol该酯完全水解可得到1mol羧酸和2mol乙醇，该羧酸的分子式为（）

A.C14H18O5

B.C14H16O4

C.C14H22O5

D.C14H10O5

钳工划线就是在工件上按图纸和其它要求确定出加工所需要的（）。

A.尺寸

B.距离

C.界线

D.图样