Throwing tomatoes﹣Spain（西班牙）

    Spain takes "tomatoes fights" to a whole new level. But the tomatoes are being thrown, not eaten. The festival takes place during the last Wednesday in August. Trucks（卡车）carry tomatoes into the square. People rush to the tomatoes and throw them into the crowd.

Rolling cheese﹣England

    This festival is celebrated on the last Monday in May. It takes place on Cooper's Hill. A large wheel of cheese（奶酪）is rolled down Cooper's Hill. The festival is actually a race where people run down the hill after the rolling cheese. The first person to cross the finish line at the bottom of the hill wins the cheese.    

Burning man﹣The United States

    The Burning Man Festival lasts a week, it is from the Monday before labor Day to Labor Day（which falls on the first Monday in September in America）. The festival takes place in the Black Rock Desert. The best part of the festival is the burning of a large sculpture of a man.

Pouring water﹣Thailand

    The Songkran Festival is the celebration of the New Year in Thailand. Rather than a single day. Thailand celebrates the New Year from April 13th to April 15th. Thai people run after each other pouring water. Songkran is one of the most important reasons why foreigners travel to the beautiful land.

实验

药品

制取气体

量气管中的液体

Ⅰ

Cu、稀HNO₃

H₂O

Ⅱ

NaOH固体、浓氨水

NH₃

Ⅲ

Na₂SO₃固体、浓H₂SO₄

SO₂

Ⅳ

镁铝合金、NaOH溶液（足量）

H₂

H₂O