短文改错

    My swimming experience is extreme interesting. There was a time when I swim like a rock.This went on till one day when I was fishing with a friend of mine at nearby pond. I was so much careless that I slipped into one. Had my friend not come to my rescue, I would have be drowned. Ever since then, I have come to know the importance of learn to swim. I didn't go to any training class but  learned it all by me. Now I have no difficult swimming at all . Though the way I swim looks clumsy ,at least it can keep me floating. Thinking of this, I feel quite satisfying.

我国公民应履行的基本义务有（）
①维护国家统一和民族团结             ②受教育
③言论、出版、集会、游行             ④依法纳税 

七年级学生李明在网上参加一次“有奖调查”，填写了父亲的姓名、电话等基本信息。不久，他的父亲在外地接到电话。听说李明正在医院紧急抢救需要两万元，急忙向对方账户汇款，最后发现被骗了。这件事告诉我们（    ）

①不要接受任何形式的问卷调查           ②不能轻易向陌生人透露家庭信息

③ 要提高警惕，增强自我保护意识      ④不能轻易相信陌生电话