根据短文内容，选择正确答案。
B
    Nick is my pen pal. He is 12 years old. He is from Canada. He lives in Ottawa. He speaks English and French. His favorite subject is science. He likes Chinese, too. And he says he can speak a little Chinese, but he can't write in Chinese.
    Nick likes sports, too. He likes swimming best. He goes swimming on weekends with his father. He says he can swim very well. He doesn't like physics. He thinks it's too difficult.
    Nick has a big family. There are nine people in his family, his grandpa, grandma, father, mother and his brothers and sisters. He has two brothers and two sisters. They are Bob, Tim, Jane and Susan. They are happy!

年初，我国东部地区出现大范围、长时间的雾霾天气，严重影响人们的生产生活．下列哪些出行方式能为减少雾霾天气作出贡献（　　）

①步行   ②骑自行车   ③骑摩托车   ④开私家车   ⑤乘公交车．

力F₁单独作用在物体A上时产生的加速度大小为a₁=5m/s²,力F₂单独作用在物体A上时产生的加速度大小为a₂=1m/s².那么，力F₁和F₂同时作用在物体A上时产生的加速度a的大小范围是：

阅读下面一段文字，根据拼音填写汉字。

       建筑是无声的诗歌，建筑是níng____固的音乐。巍峨、雄伟、庄严的人民英雄纪念碑，钟山南lù____巍巍的中山陵，气势hóng____伟、金bì____辉煌的法国凡尔赛宫，体现我国古代建筑艺术特色的黄鹤楼和于园，从这些建筑，我们可以看到历史的印记和社会发展的足迹，可以领悟到人类的勤劳、智慧和对美的追求。

若，则函数的最小值为（    ）