向CuO和铁粉的混合物中加入一定量的稀硫酸，微热，充分反应后冷却，过滤，在滤液中放入一枚洁净的铁钉，发现铁钉表面无任何变化，据此判断下列结论正确的是（　　）

如图所示，在“探究物体的动能大小与哪些因素有关”的实验中，小球由斜面某位置滚下，撞击水平面上的小木块．

 选词填空：阅读下面材料，用方框中所给单词的适当形式在空白处填空，每词限用一次，每空只能填一词。

There ____   four people in this family. Mr. Green is a policeman. He works very____  from Monday to Saturday. He walks his dog every day ____    dinner for an hour.

Mrs. Green is a teacher in a school. Her  ____   are young and naughty. She often plays badminton with them after school.

Tom is Mr. Green`s son . He is only sixteen years old. After he ____    his homework, he often plays basketball with his friends.

Linda is  ____  sister. She is only eight years old. She has  ____ homework than Tom . She often plays the piano at home.

They are all ____    in dancing. They often have a family party on weekend. At the party, they usually play the music ____     they can dance to.

指出下列各句所用的表达方式。

茅盾故乡乌镇的小河两岸都是密密的芦苇，真是密不透风，每当其间显现一座石桥时，仿佛发闷的苇丛做了一次深呼吸，透了一口舒畅的气。____

阅读下面的文言语段《炳烛夜谈》，完成下面小题。

       晋平公问于师旷曰：“吾年七十，欲学，恐已暮矣。”师旷曰：“何不炳烛^①乎?”平公曰：“安有为人臣而戏其君乎?”师旷曰：“盲臣^②安敢戏君乎?臣闻之：少而好学，如日出阳;壮而好学，如日中之光；老而好学，如炳烛之明。炳烛之明，孰与昧^③行乎?”平公“善哉!”。

      【注释】①炳烛：点烛。②盲臣：师旷为盲人，故自称盲臣。③昧行：在黑暗中行走。