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举一反三
【单选题】Desperately short of living space and dangerously prone to flooding, the Netherlands plans to start building homes, businesses and even roads on water. With nearly a third of the country already cover...
A.
most parts of the country are covered by water
B.
the country is constantly threatened by floods
C.
it will promote the cultivation of flowers
D.
people think it better to live on water
【单选题】四元轴烯t、苯乙烯b及立方烷c的分子式均为C 8 H 8 。下列说法正确的是( )
A.
b的同分异构体只有t和c两种
B.
t、b、c的二氯代物均只有三种
C.
t、b、c中只有t的所有原子处于同一平面
D.
t、b、c中只有t和b能使酸性KMnO4溶液褪色
【单选题】下列有关物质分类正确的是①合物：盐酸、王水、水玻璃、水银②化合物：CaCl2、烧碱、聚苯乙烯、HD③电解质：H2SO4、胆矾、冰醋酸、硫酸钡④同素异形体：C60、C70、金刚石、石墨
A.
①③
B.
②④
C.
②③
D.
③④