烟斗和雪茄比香烟对健康的危害明显要小。吸香烟的人如果戒烟的话，则可以免除对健康的危害，但是如果改吸烟斗或雪茄的话，对健康的危害和以前差不多。如果上述断定为真，则以下哪项断定最不可能为真？
A．香烟对所有吸香烟者健康的危害基本相同。
B．烟斗和雪茄对所有吸烟斗和雪茄者健康的危害基本相同。
C．同时吸香烟、烟斗和雪茄所受到的健康危害，不大于只吸香烟。
D．吸烟斗和雪茄的人戒烟后如果改吸香烟，则所受到的健康危害比以前大。
E．烟斗比雪茄对健康的危害要大。

One of the questions that is coming into focus as we face growing scarcity of resources of many kinds in the world is how to divide limited resources among countries. In the international development community, the conventional wisdom has been that the 2 billion people living in poor countries could never expect to reach the standard of living that most of us in North America enjoy, simply because the world does not contain enough iron ore, protein, petroleum, and so on. At the same time, we in the United States have continued to pursue super affluence as though there were no limits on how much we could consume. We make up 6 percent of the world's people; yet we consume one-third of the world's resources.
As long as the resources we consumed each year came primarily from within our own boundaries, this was largely an internal matter. But as our resources come more and more from the outside world, "outsiders" are going to have some say over the rate at which and terms under which we consume. We will no longer be able to think in terms of "our" resources and "their" resources, but only of common resources.
As Americans consuming such a disproportionate share of the world's resources, we have to question whether or not we can continue our pursuit of super affluence in a world of scarcity. We are now reaching the point where we must carefully examine' the presumed link between our level of well-being and the level of material goods consumed. If you have only one crust of bread and get another crust of bread, your well-being is greatly enhanced. But if you have a loaf of bread, then an additional crust of bread doesn't make that much difference. In the eyes of most of the world today, Americans have their loaf of bread and are asking for still more. People elsewhere are beginning to ask why. This is the question we're going to have to answer, whether we're trying to persuade countries to step up their exports of oil to us or trying to convince them that we ought to be permitted to maintain our share of the world fish catch.
The prospect of a scarcity of, and competition for, the world's resources requires that we reexamine the way in which we relate to the rest of the world. It means we find ways of cutting back on resource consumption that is dependent on the resources and cooperation of other countries. We cannot expect people in these countries to concern themselves with our worsening energy and food shortages unless we demonstrate some concern for the hunger, illiteracy and disease that are diminishing life for them.
The writer warns Americans that ______.
A．their excessive consumption has caused world resource exhaustion
B．they are confronted with the problem of how to obtain more material goods
C．their unfair share of the world's resources should give way to proper division among countries
D．they have to discard their cars for lack of fossil fuel in the world

By "common resources" （Paragraph 2), the author means that ______.
A．the resources possessed by the United States should be shared by other countries
B．Americans have the right to consume resources both from their home country and from abroad
C．it is difficult to distinguish the resources possessed by America from those possessed by other countries
D．all the resources in the world should be shared by all the countries

具有高效发动机的天蝎座节油型汽车的价格高于普通的天蝎座汽车。以目前的油价计算，购买这种节油型车需要开6000公里才能补足与买普通型车的差价。因此，如果油价下跌，在达到这个破平点之前就可以少走了些路。以下哪项中的错误与上文最为类似？
A．真实储蓄利率是由储蓄利率减去通货膨胀而成的，所以，如果通货膨胀率下降，在真实储蓄利率不变的情况下，储蓄利率也要降低相同的比例。
B．对食品零售店来说，与乙牌冰箱相比，甲牌冰箱能为负担额外的冰冻食品提供一个恒定温度，尽管甲牌冰箱的耗电量较大，但出售额外食品却能获得更多的利润。因此，如果电价下降，零售店就应当选择甲牌冰箱。
C．用甲牌沥青比用乙牌沥青能使修路工人用更短的时间铺完一公里的路。尽管甲牌的价格较高，但减少施工人员所省下来的钱是可以补足沥青价格差异的。所以，在劳动力价格低廉时，选择甲牌沥青更有优势。
D．改良过的北方苹果树结果更早，存活期更长。原来的苹果树虽然结果较大，但需要较大的种植间距。所以，新种植的苹果树应全部使用改良种。
E．每年根据上市公司赢利状况的不同进行股票分红。债券则年年获得相同的利息，因此，由于债券利率在经济危机时并不下降，喜欢稳定收入的人的投资者应该选择债券。

平面直角坐标系中，A（3，5)，B（a，7)，C（-1，6)三点共线。
A．条件（1)充分，但条件（2)不充分。
B．条件（2)充分，但条件（1)不充分。
C．条件（1)和（2)单独都不充分，但条件（1)和条件（2)联合起来充分。
D．条件（1)充分，条件（2)也充分。
E．条件（1)和（2)单独都不充分，条件（1)和条件（2)联合起来也不充分。

尽管幼儿园老师反复叮咛，我的孩子总难以养成临睡前刷牙的习惯。我做出样子，希望她能够模仿；我给她讲道理，临睡前刷牙甚至比清晨更重要，但总难以奏效。后来，我在她临睡前给她讲一个故事，并要求她听故事前去刷牙。几周后，每天晚上临睡前，只要我一拿起故事书，她就会立即去刷牙。以下哪项是对上述家长经验的最恰当概括？
A．喜欢听故事是幼儿的天性，家长应学会运用这一点对孩子进行有益的诱导。
B．家长在教育幼儿方面比幼儿园老师更有效，是因为他们对孩子更具爱心。
C．榜样比说教对幼儿更有效。
D．孩子的习惯是靠重复某个行为养成的，即使她并不理解这一行为的意义。
E．幼儿更愿意去模仿大人的行为，而不愿意听从大人的要求。