问题
选择题
下列反应肯定是吸热反应的是
A．轻质油裂解
B．酒精燃烧
C．葡萄酿酒
D．苯的溴代
答案
答案：A
酒精燃烧、葡萄酿酒均为氧化反应，放热；苯在铁的催化作用下溴代放出大量的热，故答案为A：裂解需要外界提供能量使大分子断裂为小分子；故选A
搜题请搜索小程序“爱下问搜题”
下列反应肯定是吸热反应的是
A．轻质油裂解
B．酒精燃烧
C．葡萄酿酒
D．苯的溴代
答案：A
酒精燃烧、葡萄酿酒均为氧化反应，放热；苯在铁的催化作用下溴代放出大量的热，故答案为A：裂解需要外界提供能量使大分子断裂为小分子；故选A
If you are lost in the mountain, don’t get nervous. Staying calm will greatly your chances of survival. Many people think that good preparation is very . But actually the most important thing is to keep calm. In order to survive, you can do the following things. First, find a hiding place. Unnecessary movement will make you . You’d better find a hiding place to rest in order to save your . If you are in snow, you may be able to dig a cave for protection the cold weather. Second, send a signal(信号) to searchers for help. The best time to a signal for help is during the day. Do this from the point. It will be easier for searchers to see you. If you take a box of matches, build three smoky fires with some dry branches and the will tell other people where you are. Third, do not walk away. Walking away will make it more difficult to find you, searchers will try to follow your path and may you if you have gone off in a different direction. Searchers often find a car with no one in it.
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