题干

最近,科学家用巨型计算机进行模拟后确认,由60个N原子可结合成N60分子,N60变成 N2时放出巨大能量,下列说法中不正确的是(   )

A:N60与N2都是氮的同素异形体

B:N60转化为N2属化学变化

C:N60的总能量高于N2的总能量

D:N60变为 N2的反应是放热反应,说明N60比N2更稳定

上一题 下一题 0.0难度 选择题 更新时间:2011-08-09 10:23:47

答案(点此获取答案解析)

D

同类题1

          The production of coffee beans is a huge, profitable business, but, unfortunately, full-sun production is taking over the industry and
 bringing about a lot of damage. The change in how coffee is grown from shade-grown,production to full-sun production endangers the very existence of, certain animals and birds, and even disturbs the world’s ecological balance.
          On a local level, the damage of the forest required by full-sun fields affects the area’s birds and animals. The shade of the forest trees provides a home for birds and other special(物种) that depend on the trees’ flowers and fruits. Full-sun coffee growers destroy this forest home. As a result, many special are quickly dying out.
        On a more global level, the destruction of the rainforest for full-sun coffee fields also threatens(威胁)human life. Medical research often makes use of the forests' plant and animal life, and the destruction of such species could prevent researchers from finding cures for certain diseases. In addition, new coffee-growing techniques are poisoning the water locally, and eventually the world's groundwater.
         Both locally and globally, the continued spread of full-sun coffee plantations (种植园)could mean the destruction of the rainforest ecology. The loss of shade trees is already causing a slight change in the world's climate,
 and studies show that loss of oxygen-giving trees also leads to air pollution and global warming. Moreover, the new growing techniques are contributing to acidic(酸性的) soil conditions.
         It is obvious that the way much coffee is grown affects many aspects many aspects of life, from the local environment to the global ecology.
 But consumers do have a choice. They can purchase shade-grown coffee whenever possible, although at a higher cost. The future health of 
the planet and mankind is surely worth more than an inexpensive cup of coffee.