统计给定文本中每个单词出现的次数，并按照出现频率从高到低排序，给出前10个单词和它们的出现次数。
The quick brown fox jumps over the lazy dog. The dog barks at the fox but the fox keeps running. The fox is too quick for the dog.
quick: 2
the: 4
fox: 3
dog: 2
jumps: 1
over: 1
lazy: 1
barks: 1
but: 1
keeps: 1

Top 10:

the: 4
fox: 3
quick: 2
dog: 2
jumps: 1
over: 1
lazy: 1
barks: 1
but: 1
keeps: 1