根据短文内容及首字母提示，填写所缺单词，使短文意思完整，每空只填一词。
    Millions of American children attend summer camp. Traditional American summer camps offer young people a c____  to play many sports. These camps may be in the mountains. Or they may be in the woods, or at a lake. O____   camps teach activities like painting or music. Or t____ teach computer programming or foreign languages. Children at all kinds of camps m____  new friends. They learn new skills and develop independence (独立).
    Some children go to camp d____  the day and return home at night. These places are c____  day camps. Children as y____  as four years old attend day camps. Others stay at camp all day and all night. Most children w____  attend overnight camp are between the ages of about six and sixteen.
    Children s____  at an overnight camp for between one and eight weeks. P____  can pay less than one-hundred dollars a week for an overnight camp. Or they can pay more than seven-hundred dollars a week.

长江经济带上、中、下游地区面临产业合作和结构优化升级、完善产业转移和承接等重要任务。中游大部分地区产业吸引能力较弱的最主要原因是（    ）

全要素生产率是衡量单位总投入的总产量的生产率指标，即总产量与全部要素投入量之比。全要素生产率的增长率常常被视为科技进步的指标，以下属于提高全要素生产率的途径是（  ）

①掌握系统优化方法，优化配置生产要素

②抓住主流，不断增强国有经济的控制力

③用发展观点看问题，推动产业结构优化升级和科学技术创新

④坚持两点论与重点论的统一，实行更加积极主动的开放战略