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问题 选择题

已知a、b、c都是负数，且|x-a|+|y-b|+|z-c|=0，则xyz是（　　）

A．负数

B．非负数

C．正数

D．非正数

答案

∵|x-a|+|y-b|+|z-c|=0

∴|x-a|=0，|y-b|=0，|z-c|=0

∴x=a，y=b，z=c，

又∵a、b、c都是负数，

∴xyz是负数．

故选A．

填空题

According to traditional Cherokee beliefs, we are part of (1) . We don’t (2) with it and we’re not trying to (3) it. We are a part of the Great Life. And within the Great Life, there are three great Laws of Nature, which tell us how we have to live in (4) with everything else. The First Law of Nature is that you don’t take any life without real (5) . So we shouldn’t (6) needlessly. We believe everything is alive, including animals, plants and (7) . And so to us, taking the life of a plant is just as grave a 8() as taking the life of an animal. The Second Law is that everything we do should (9) the Great Life. And everything we do (10) the Great Life, and everything that (11) within the Great Life affects us. So it’s very important that what we do will not (12) other parts of the Great Life. The Third Law basically is that we don’t (13) where we live. And where we live is not our (14) , small community. It’s this (15) . We don’t pour chemical (16) down the drain because they all wind up in the water. It might seem a little difficult to live by those three laws in this (17) society. But there are still a lot of things that we can do to bring these laws into our lives, such as (18) , using the (19) as little as possible, and (20) gardening.
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选择题

朝核问题是当今世界的一大热点，也是中国周边重要的安全因素之一。为了和平解决这一问题，中国进行了积极的外交斡旋，成功主办了朝核问题多轮会谈并继续发挥重要作用。这表明[ ]

①中国奉行互信、互利、平等和协作的新安全观②国际社会意识形态的斗争已经终结③中国主张和平解决国际政治冲突问题④中国的国际地位在提高

A．①②③

B．①②④

C．②③④

D．①③④
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