一条老狗
an old───一位老人
old dog───老狗（电影名，OldDog）；老手；[电影]老狗；老家伙；上了岁数的人
an old house───旧房子
an old skirt───一条旧裙子
the old dog───老狗
an old shirt───旧衬衫
an old hand───老手；行家；熟练工人；老门槛
an old email───一封旧邮件
an old woman───一位老妇女；一个老太太；老身
An old dog cannot learn new tricks.───老狗学不出新把戏。
Can't learn an old dog new tricks, as the saying is.───俗话说得好，老狗学不了新把戏。
One afternoon, an old dog ran into Ben's yard.───一天下午，一只年迈的狗跑进本的院子里。
You're never going to teach your father at the age of 79 to use a computer. You can't teach an old dog new tricks, you know.───不要指望教你79岁的老父亲学会电脑。年长的人学不会新事物。
The man sat at the side of the road and sold matches, and there was always an old dog near him.───那个人坐在路边卖火柴，身边总是伴着一条老狗。
"Who said you can't teach an old dog new tricks? " Grandma ginned as she hung her college degree in computer science on the wall.───“是谁说老人难有改变呢？”外婆在将她的电脑学分挂到墙上时微笑著说。
Jimmy was an old dog and his fur was a mix of gray, brown and black. He was almost deaf, so he always wore a hearing aid.───吉米年纪很大了，而且身上的毛呈杂色：有一点儿灰，有一点儿黄，还有一点儿黑，他的耳朵也差不多聋了，所以总是带着助听器。
He looked just like an old dog gnawing on a bone.───他看来活像啃骨头的老狗。
My old uncle has become immutable in his ways, and you know that you can't teach an old dog new tricks.───我舅舅年纪很大，做事的方法都一成不变，正如大家所知道的，老狗学不会新把戏。
An old dog barks not in vain.
You cannot teach an old dog new tricks.
An old dog cannot learn new tricks.
An old dog will learn no new tricks.
Teach an old dog new tricks.
An old dog bites sore.
An old dog cannot alter its way of barking.
You can't teach an old dog new tricks.
Stop trying to teach an old dog new tricks; you are just wasting time.