若想提高冬暖大棚中蔬菜的产量，可采取下列哪些措施？（  ）

①增加二氧化碳浓度

②增加氧气浓度

③适当延长光照时间

④形成高温环境

⑤人工形成昼夜温差较大的条件

⑥多施化肥

    I'm Lucy. There are four people in my family. They are my grandfather, my parents and me. My grandfather likes to plant flowers. He works on his farm every morning. My father likes to watch TV. He likes to watch the news very much. My mother likes to go shopping. She often buys new clothes for us. I like to read books. I go to the library on Sundays.

综合性学习。
        土地是人类活动的舞台，是人类赖以生存的基础，土地关系到社会的稳定，人民的幸福，所以历朝历代都非常重视对土地的管理。现在，全世界都面临着共同的问题：土地危机！
        班上将开展以“土地”为主题的综合性学习实践活动，要求全班都行动起来，调查了解目前我国的土地状况。