思考题：在对某地区的一次人口抽样统计分析中，各年龄段（年龄为整数）的人数如下表所示：

根据此表回答下列问题：

（1）样本中年龄在60岁以上（含60岁）的频率是多少？

（2）如果该地区现有人口80000人，为关注人口老龄化问题，请估算该地区60岁以上（含60岁）的人口数．

下列句子中划线词语使用不恰当的一项是（    ）

阅读材料，综合运用所学知识回答问题。

材料一： 1955年，周恩来总理率领中国代表团出席万隆会议，在发言中说道：“中国代表团是来求团结而不是来吵架的”“中国代表团是来求同而不是来立异的”“为了维护世界和平，我们处境大致相同的亚非国家首先应该友好合作，实现和平共处。过去殖民统治在亚非国家间所造成的不和与隔阂，不应该继续存在。我们应该互相尊重，消除互相间存在的疑虑和恐惧”。周恩来的发言赢得了全场经久不息的掌声。

材料二： 2015年4月22日至24日，***出席亚非领导人会议和万隆会议60周年纪念活动，并发表题为《弘扬万隆精神 推进合作共赢》的重要讲话。***主席从全球角度把握和平、发展、合作、共赢的时代潮流，倡言三大合作发展路径，引发广泛共鸣。中国以负责任大国的担当和气度，以合作共赢的诚意和胸襟，以命运共同体的引领与践行，赢得了国际社会的热烈称赞。

材料三： 中国改革开放取得了巨大成就，国际地位空前提高，这给中国的对外交往提供了强大的物质基础。在中国政府的主动坚持下，中国顺利收回了整个香港地区和澳门的全部主权，扫除了全部殖民耻辱……中国已成为世界经济增长的重要引擎，世界与中国一起从中国的发展中获益。

    I was having a period of bad health. I had one operation after another. I was falling 1 faster than the doctors could put me back together. But I just couldn't bear the operation, the hospital stay, the long recovery and the physical therapy（康复治疗）. I told my doctor I was going to try 2 else.

    I'd discovered that walking gave me a little 3. So I started walking. The first day, my wife 4 off our steep Silver Lake hill to a flat street. She got me out of the car, and I walked about two blocks 5 asking to be taken home. The next day, I walked about four 6.

    Slowly, feeling a little 7 every day, I began to walk a mile or more. I even 8some hills to my route. I became interested in the network of public stairways around Silver Lake I made a 9 of it and walked every public staircase in Silver Lake. That went pretty well, so I 10 onto Echo Park. I was feeling better, so I kept going. The search finally 11 “Secret Stairs: A Walking Guide to the Historic Staircases of Los Angeles' a book 12 in the spring of 2010. By then, I had 13. I'd been walking at least an hour a day for three years. My life 14 returned to normal.

    In three years of walks, I've met dozens of people who'd had 15 experiences of rebirth or recovery. One man told me he'd lost 80 pounds walking the secret stairs and was dating for the first time in a decade. One woman told me she'd 16 knee operation. Another told me she'd been 17 to start ballroom dancing again.

    All I'd 18 from the walks was relief from pain. What I got was 19, community and a whole new experience of my city. Out of the car, on my feet and moving at walking pace, I 20 Los Angeles for the first time.

已知一个圆经过直线l：2x+y+4=0和圆C：x²+y²+2x﹣4y+1=0的两个交点，且有最小面积，求此圆的方程．