Ⅱ 语言知识及应用（共两节，满分35分）
第一节 完形填空（共10小题；每小题2分，满分20分）
阅读下面短文，掌握其大意，然后从21～30各题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。
There was once a scientist. After a lot of practice and efforts, he learned the art of reproducing himself. He did it so 21 that it was impossible to tell the reproduction from the original.
