根据短文内容和首字母的提示，把所缺单词完整地填写在短文后的横线上。
Nowadays, it's common to keep dogs as pets. We can often see dogs' owners taking them for a walk.
But have you (1)h______ of taking penguins for a walk? Here (2)i______ a piece of news from Japan. In
Tokyo Zoo, penguins go out for a walk in line every day. It is said that this can make them happy and stop
them from being homesick (想家的). The penguins in the zoo didn't eat as (3)w______ as they did in South
Pole (南极) and they were (4)u______ to the keepers when they first got to the zoo, maybe they were not
used to the life in the zoo. So the zoo keepers (5)c______ up with this good idea. They just let them walk
as they did in South Pole. Now, all these penguins have become happy.
