下图中的阴影部分表示在四个地区分布的四种农作物。根据图中提供的信息，回答下列问题。

        Tom and Fred were talking about the year 2050.
　　“What will 1 be like in the year 2050?” asked Tom.
　　“I don't know,” said Fred. “What do you think?”
　　“Well, no one knows. But it is 2 to guess,” said Tom. “In the year 2050 everybody will carry a pocket (袖珍) 3. The computer will give people the 4 to all their problems. We shall all have telephones in our pockets,5 . And we'll be able to talk to our friends all over the world. Perhaps(也许) we’ll be able to 6 them at the same time. Machines will do 7of the work, and people will have more8. Perhaps they will work only two or three days a week. They will be able to fly to the moon by spaceship and spend their holidays there.”
　　“I'm very 9to hear that. I hope to fly to the moon. And I hope I'll be able to live 10,” said Fred. “Won't that be interesting? Just like a fish.”

1979年某地一位农民做裤子卖，一天挣的钱比在地里刨一年还多。远近农民纷纷仿效，这引起了轩然大波。民兵围追堵截，工商税务补税罚款，然而，撵了集中的却撵不了分散的，裤子交易仍在进行。到1984年，该地裤子市场终于名正言顺。结合所学知识，对此认识中不正确的是（   ）

下列以对联的形式描绘出我国各省区的突出特点。例如①“苍松雪岭，沃野龙江稻谷香”，②“碧草毡房，春风马背牛羊壮”，③“琼海独具大手笔，五指擎天”，④“石林自有高材生，群峰拔地”。以上四句对联描述的分别是（     ）

实验一：用弹簧秤拖动木块在水平木板上运动

实验二：用弹簧秤拖动木块在垫有毛巾的水平木板上运动

实验三：用弹簧秤拖动放有砝码的木块在水平木板上运动

回顾课堂上的实验过程回答问题：