491.  The sailor was nailed on the rail for he failed to trail the mail.

水手被钉在横木上，因为他未能跟踪邮件。

492.  The frank man put the first-rank blank blanket into the tan tank.

直率的男子将一流空白毛毯放进黝黑的大容器

493.  Thanks to the bankrupt banker, my ankle avoided an injury.

多亏那位破产的银行家，我的脚踝免受伤害。

494.  After a shot the foot began to root and shoot in the boot.

打了一针后，脚开始在靴子里生根发芽。

495.  The academic topic is why the blade of the spade is still sharp after decades' decay.

学术话题是为什么铁锨刃口经过几十年的腐烂之后仍然锋利。

496.  The invader¹ saw the shadow of the lampshade fade away.

入侵者看见灯罩的影子渐渐消失。

497.  The graduated comrade gradually graded the trademarks² after the parade.

阅兵过后，那位毕了业的同志逐渐将商标分了等级。

498.  Both the math pathfinders bathed in the bathtub.

两个数学先驱都在浴盆里洗过澡。

499.  In the thesis the synthetic³ symbol symbolizes⁴ sympathy.

在论文中这个综合符号代表同情。

500.  For unity⁵ the units united into a unique union.