阅读下面短文，从短文后各题所给的四个选项（A，B，C，D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
As a general rule, all forms of activity lead to boredom when they are performed on a routine（常规）basis. As a matter of fact, we can see this 　_ 41 _ at work in people of all　 _ 42 _ . For example, on Christmas morning, children are excited about _ 　43 _ with their new toys. But their _ 44 _ soon wears off and by January those _ 45 _ toys can be found put away in the basement. The world is full of 　 _ 46 _ stamp albums and unfinished models, each standing as a monument to someone’s　 _ 47 _ interest. When parents bring home a pet, their child　 _ 48 _ bathes it and brushes its fur. Within a short time, however, the　 _ 49 _ of caring for the animal is handed over to the parents. Adolescents enter high school with great　 _ 50 _ but are soon looking forward to　 _ 51 _ . The same is true of the young adults going to college. And then, how many　 _ 52 _ 　, who now complain（抱怨）about the long drives to work, 　 _ 53 _ 　 drove for hour at a time when they first 　 _ 54 _ their driver’s licenses （执照）? Before people retire, they usually　 _ 55 _ to do a lot of　 _ 56 _ 　 things, which they never had　 _ 57 _ to do while working. But _ 58 _ 　 after retirement, the golfing, the fishing, the reading and all of the other pastimes become as boring as the jobs they　 _ 59 _ . And, like the child in January, they go searching for new 　 _ 60 _ 　.