给定一篇英文文本，要求提取其中所有的单词并计算其一元词频（某个单词出现的次数）和二元词频（两个连续单词出现的次数）
举例:I have an apple . And you have an apple , too .
输出: i--1，have--2，an--2，apple--2，and--2，you--1，too--1
an apple--2
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001059s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.066321s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001056s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001331s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000994s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003186s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000871s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003742s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015513s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001181s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 64490 [ RunTime:0.015055s ]
