Tom and Fred are talking about the year 2020．"What will our world be like in the year 2020?""I don't know."says Fred．"What do you think?""Well, no one knows, but It's interesting to guess.""In the year 2020 everyone will carry a pocket computer. The computer will give people the answers to all their problems. We shall all have telephones in our pockets, too, and we'll be able to talk to our friends all over the world. Perhaps we'll be able to see them at the same time.""A lot of people will live and work under the sea. Perhaps there will be big towns, factories and farms under the sea, too.""Machines will do most of the work, and so people will have more holidays, perhaps they'll work only two or three days a week. They'll be able to fly to the moon by spaceship and spend their holidays there.""I'm looking forward(期待) to the year 2020. I hope to go to the moon!""And I hope I'll be able to live under the sea."says Fred."Won't that be very interesting? Just like a fish!"
【小题1】Tom and Fred talked about          ．

A．their school life

B．some interesting news

C．their life in the past

D．their life in the future

【小题2】Machines will          ．

A．do most of the work instead of people

B．do some of the work instead of people

C．do as much work as people

D．do as 1ittle work as people

【小题3】From their talk, we know that          ．

A．only Fred hopes to fly to the moon

B．both of them hope to fly to the moon

C．one of them hopes to fly to the moon

D．neither of them hopes to fly to the moon

【小题4】Fred said          ．

A．he liked fish very much

B．he would like to live under the sea like a fish

C．he would go fishing under the sea

D．he would spend a few days on the moon

【小题5】Which of the following statements is Not mentioned?

A．People will be able to fly to the moon in a spaceship．

B．People will have more holidays．

C．Many people will live and work under the sea．

D．All the factories and farms will be built under the sea．

我们每天都和化学变化打交道，下列叙述不是化学变化的是

A．人吃进的食物逐渐被消化	B．人体的呼吸作用
C．使用煤气作燃料烧饭做菜	D．水在冰箱里结成冰

下列四个短语，其原意一定包含化学变化的是

A．花香四溢

B．海市蜃楼

C．百炼成钢

D．木已成舟

下列四个短语，其原意一定包含化学变化的是

A．花香四溢

B．海市蜃楼

C．百炼成钢

D．木已成舟

下列四个短语，其原意一定包含化学变化的是

A．花香四溢

B．海市蜃楼

C．百炼成钢

D．木已成舟

中国共产党自建党以来，据统计先后召开会议八百余次。这些会议整体反映了中国共产党八十多年来艰辛而又光辉的历程。其中七届二中全会、八大、十一届三中全会在我国社会主义发展史上具有划时代的意义。
请回答：   
(1)分别指出上述三次会议在社会主义经济建设方面具有延续性的决策。作出这些决策的有利国际因素是什么?(8分)
(2)上述三次会议在指导党的建设方面先后提出了哪些方针?(3分)   
(3)在开创社会主义事业新局面的历程中，三次会议具有怎样的历史地位?(3分)

下列物质属于纯净物的是(    )

A．食醋

B．白酒

C．糖水

D．蒸馏水

下列物质属于纯净物的是(    )

A．食醋

B．白酒

C．糖水

D．蒸馏水

计算：
（1）        
（2）

解方程：
（1）                
（2）
(3)关于的方程与方程同解,求