实验室备有甲、乙、丙三个凸透镜，三个实验小组分别用这三个凸透镜探究凸透镜成像规律，实验时，当蜡烛到透镜的距离都为12cm时，甲、乙、丙三透镜分别成缩小的实像、放大的虚像、放大的实像，则这三个透镜的焦距f_甲、f_乙、f_丙的大小关系为(  )

（Ⅰ）求函数f（x）的最小正周期与单调增区间；

（Ⅱ）求函数f（x）在 $0,\frac{\pi }{4}$ 上的最大值与最小值．

2017年全国两会期间，中国政府网开展“我向总理说句话”网民建言征集活动·网友可以通过论坛、微信等平台建言献策。这一活动有利于

（   ）

  ①提高公民的参政意识    ②决策的民主化和科学化

  ③保障公民的政治权利    ④人民直接行使国家权力

    Animals are our friends.There are many many zoos in the 1. It's good to 2 animals in zoos.Zoos have many advantages, I think.

    Firstly, zoos are places for people to see 3 kinds of animals. Without zoos, most people would 4 see a real bear or tiger.

    5, zoos can take good care of animals. Zoos give 6 to animals and clean them on time every day. In the wild(在野外), it is not always easy for an animal to find food. So sometimes it goes 7^. But animals in zoos never go hungry.

    Thirdly, people protect the animals in zoos and offer them safe places to live 8^. Animals are living in zoos safely and happily. In the wild, some kinds of animals are 9 and are endangered(濒危的). But zoos give these animals a chance to live. Without zoos, there would be 10 kinds of animals in the world. People should do more things to protect animals.