截至2017年3月6日，我国共发射15颗风云气象卫星，为防御气象灾害提供有力保障。风云气象卫星发射以来对登陆的200多个台风都进行了有效预报，路径误差保持在70公里之内；24小时之内的气象预报准确率提高到87%。这说明（    ）

①气象预报既体现世界具有可知性，又体现认识的有限性

②气象预报手段的不断完善，深化人们对气象规律的认识

③气象卫星延伸了人类认识器官，改变天气变化的无序性

④气象卫星数量增加，必然使人类防御灾害能力实现飞跃

以下是上海某13岁学生在与同学交往中发生的几件小事：
小事一：他擦鼻涕时，发现自己带的纸巾用完，向某同学借两小包豆腐干大小的纸巾，按市价为0.6元，对方却要他还8元。
小事二：他因玩同学的电子玩具出了毛病，对方除了要他负担修理费外，还要求赔偿“精神损失费”，并限定在规定时间归还，如超期就加倍偿还，因为不放心，还要他打“欠条”。
小事三：他因喝袋装牛奶，自己剪子找不到，向同学借剪刀一用，对方提出以一袋牛奶作为交换。
小事四：学校组织学生到苏州某公园秋游，他自带茶水喝完，想跟其他同学要点水喝，对方却要他用价值10多元的零食来换。
对上述现象认识正确的是                                                 （   ）

Farmers in poor areas cannot afford to ________ a doctor when they get sick.

    Are you ready for adventure (冒险)? Then Sunny Shores Sea Camp is the place for you! The activities there are all about the sea.
At Sunny Shores Sea Camp, you can get excited and improve your skill-level. You can enjoy the wonders of Sunny Island. From diving（潜水）to sailing, sea science to seafood, Sunny Shores Sea Camp offers courses for your different interest. You can also learn about the sea environments of Sunny Island. It is hard for you to find anywhere else like that.
    Whether you're a beginner or already an expert (专家), Sunny Shores Sea Camp is a great place that brings together campers from all over the world.
    Wonderful memories and new friends are waiting for you at Sunny Shores Sea Camp!
Camp Activities: Adventure . Sea Biology. Diving . Sailing . Windsurfing
Camp Address: Sun Bay , South Florida 000634
Dates: June 28 - July 18 , July 21 -August 9
Cost Week: $600 - $900
Campers Ages: From 13 to 17
Contact us: Sign up at www.sunnyshoresseacamp.org! Or call 800-645-14231

我国实现环境保护的根本途径是                                      （    ）