An elderly teacher，with a pupil by his side，took a walk through a forest. Suddenly he__41__(stop)and pointed to four plants close at hand. The first was just beginning to appear slowly above the ground，the second had rooted itself pretty well into the earth，the third was a small short tree，while the fourth was__42__ full-sized tree. The tutor said to his young__43__(company)，“Pull up the first plant. ” The boy [KS5UKS5U]did so eagerly，__44__(use)only his fingers. “Now pull up the second.” The youth obeyed__45__ found that the task was__46__(difficult)．[KS5UKS5U