填动词

（摘）野果      ____蘑菇      ____野菜      ____松鼠

____蜻蜓     ____蝈蝈      ____夕阳      ____明月

东北许多工业中心的形成和发展主要是依托（    ）

阅读短文，判断正误。
Dear Joe,
    How are you? My sister and I are having our holiday. Yesterday we went to the library. We got there by bus. We read storybooks and had lunch there. The food was delicious. It was cheap, too. We went shopping in the afternoon. I bought a pair of shoes. I was very tired. We are planning to learn skating and do many other things during the holiday. We are sure we'll have a good time.
    How about your holiday? Please write to me soon.
Miss you.
Alice

如图，在四棱锥P﹣ABCD中，PA⊥底面ABCD，AB⊥AD，AC⊥CD，∠ABC=60°，PA=AB=BC，E是PC的中点．

以下是俄国化学家罗蒙诺索夫曾开展的实验：

①先用天平称取质量为m₁的金属锡粉．

②将这些锡粉放在密闭容器里进行完全燃烧，生成了白色固体物质，称量容器的总质量为m₂．

③打开容器，听到了空气进入容器发出的“丝丝的声响”，称量所得白色物质的质量为m₃．

④把白色物质放回原容器里（容器中空气的组成恢复到初始状态），重新称量容器的总质量为m₄