491.articulate v. 清楚说明
The world has had a week to conjure up nightmare scenarios, yet no one has articulated the most frightening peril posed by human cloning: rampant self-satisfaction.
世人已经有一个星期的时间来幻想各种梦魇式的景象，但是还没有人清楚说明复制人类将带来最骇人的危险：狂妄的自满。
492.assassinate v. 刺杀
While Vice President, Nixon allegedly organized an ill-fated convert plan to assassinate Fidel Castro.
据说尼克松担任副总统时，曾策划了一桩注定失败的刺杀卡斯特罗的秘密计划。
注：convert adj. 秘密的，偷偷摸摸的
493.assume v. 假定，以为
【同】presume
This occasion may have been the most important of Kennedy’s adult life so far, publicly as well as privately, and he carried it off with an imagination and delicacy that not everyone assumed he possessed.
这次婚礼该算是小肯尼迪成人后至目前，于公于私都最重要的一桩大事，而且他凭借想象力与细腻——并非每个人都认为他具有这些特质——完成此举。
494.backfire v. 招致反效果
According to Tenner, every technological endeavor is riddled with “solutions” that backfire.
按照特纳的看法，每一项科技的努力，都深受弄巧成拙的“解决方案”之困扰。
注：to be riddled with 充满……
495.banish v. 排除
【同】expel
We rewrote our legal and regulatory system in the past few decades essentially to banish human judgment from government decisions.
过去几十年我们重新写了法律体系与管理规定，基本上就是为了使政府在做决定时，将人为的判断排除在外。
496.bar v. 禁止
【同】ban
Pretoria was barred from every Olympic competition for 32 years.
南非被阻隔于奥运会外达32年。
497.bill v. 宣传
In fact, computers become outdated so fast, you’re crazy to buy anything that’s billed as “state of the art.”
事实上，电脑更新换代的速度非常快，要是去买号称“最新技术”的产品，那就太不实际了。
498.blast v. 引爆，炸开
Astronomers are not sure how our moon was formed, but increasingly they have come to suspect it was born in violence, blasted away from Earth by a collision with a planet-like object at least as big as Mars.
天文学家并不确定月球怎么形成，但越来越认为月球是在很激烈的情况下诞生，也就是说，月球是地球在撞到某个状似行星，体积至少有火星那么达的物体猛烈撞击后，迸裂出来的。
499.blossom v. 开花，出现成果
【同】bloom
Not only has their theory been confirmed, but it has blossomed into a thriving branch of research.
他们的理论不仅获得证实，而且还蔚为显学。
500.bode v. 预示
【同】augur
Nor do the ironies he culls from the history of medicine bode well for the disease-free future imagined by some prophets of biotech.
他从医学史上挑出来的一些颇具讽刺性的事件，也同样并不预示生物科技所想象出来的“无疾病的未来”。
注：cull v. 挑选