下列图片所示内容的能量转化形式是化学能经一步或多步转化为电能的是（   ）

选项	A钻木取火	B电暖扇取暖	C酒精灯燃烧	D燃煤发电
图片

_______ makes people healthy and beautiful.

下列符号只有微观意义，没有宏观意义的是（   ）

根据短文内容，选择正确答案。
Hello, friends!
    My name is Zhou Dan. I'm a Chinese girl. I'm twelve. I'm from Zhengzhou, China. Do you know Zhengzhou? It's in the middle of China. I'm in No. 8 Middle School. There are about 900 students and 50 teachers in our school. It is a good school in Zhengzhou: I'm in Class 2 Grade 7. There are 49 students in our class: 29 girls and 20 boys. My English teacher is Miss Zhao Dan. Our names are almost the same, right? She is nice to me. We're good friends. I like English, and I like music, too. I want to find a pen-friend. Please write to me.
                                                              Yours,
                                                            Zhou Dan

以下关于鸟类特征的描述正确的是（    ）。