2016届高考英语二轮复习阅读理解一百四十集选练：（100）_高考复习指南

2016届高考英语二轮复习阅读理解一百四十集选练：（100）

　　2016高考英语二轮阅读理解一百六十集选练（100）

　　2016高考训练题。阅读理解阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。For thousands of years, mankind has produced plants and animals to create more desired and useful plants and animals. For example, modern com has been produced to such a large size that it is no longer able to reproduce without man’s assistance. Modern dairy cows produce too much milk and if they are not often emptied of milk, they could leak, burst, become infected, and possibly die. Besides, most dogs raised by people can not survive in the wild even with special training.

　　Since natural evolution is extremely slow and mankind’s selective production programs only take a few generations to produce a completely new species, natural evolution has already taken a back seat to mankind’s production programs. In addition, mankind has successfully killed off several species all together. For example, there are no more European wolves in existence and mammoths (猛犸象) probably died out because of mankind. Even certain diseases have been permanently got rid of from the planet, and dozens of other diseases will soon be too. Again, natural evolution did i»t cause most of the destruction during man’s rule of the world.

　　Currently, scientists are creating new species with desired characteristics in the lab significantly faster than natural evolution creates new species. In a single generation, new species can be created and destroyed by mankind, while natural evolution could take thousands of years to do the same but only accidentally. Scientists are even able to replace defective (有缺陷的) or damaged genes with different genes to attempt to cure genetic defects. This is something that natural evolution could possibly never correct.