用电器是将电能转化为其他形式能的器件，在下列用电器中，利用电能转化为机械能的是

全部位于北半球,且被三个大洋所包围的大洲是  (    )

加热碱式碳酸铜时，观察到固体渐渐由____ 色变为____ 色，试管口有____ 生成，产生的气体能使澄清的石灰水____，证明是____ ．

选词填空，阅读下列短文，用方框内所给单词的正确形式填空

    As a student, what does it mean " to be good"? TheCode of Conduct for Primary and Middle School Students (《中小学生守则》) holds the answer.

    Last year, a new draft (草案) code came____, replacing the old content. There are some important ____. Big phrases like"have deep love for your motherland, the people and the Communist Party of China" are not there anymore. The new code tells students to respect the national flag and national emblem (国徽)____. It also ____students to "know about China's history".

    Also, the new code asks students to "lead alow-carbon (低碳的)____"，"takepart in voluntary work"， and "control the time you spend online". The change on brave actions ____draws attention. The old code told students to act bravely when they saw people ____rules. But the new code asks students to learn to protect ____and ask for help.

    Many teachers are ____to see these changes. Students say they know____to do when they face some problems.