设一个小孩在平面上沿着某曲线行走，此曲线由时间参数曲线确定。假设小孩借助于一个长度为 的硬木棒拖着或推着一个玩具，试求玩具的平面轨迹。-set up a child in a plane curve walk along this curve by the time parameter curve. Using a hypothetical child for the length of the hard wooden dragging or pushing a toy, toys trial for the plane trajectory.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002247s ]
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SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.003025s ]
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.003192s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003996s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002601s ]
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SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.016435s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.002869s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 3426 [ RunTime:0.004255s ]
