The idea of using a form of poison which could not possibly be discovered by any chemical test
使用一种用任何化学试验都检验不出的毒物，
was just such a one as would occur to a clever and ruthless man who had had an Eastern training.
这个念头正是一个受过东方式锻炼的聪明而冷酷的人所会想到的。
The rapidity with which such a poison would take effect would also, from his point of view, be an advantage.
从他的观点来看，这种毒药能够迅速发挥作用也是一个可取之处。
It would be a sharp-eyed coroner, indeed, who could distinguish the two little dark punctures
确实，要是有哪一位验尸官能够检查出那毒牙咬过的两个小黑洞，
which would show where the poison fangs had done their work.
也就算得上是个眼光敏锐的人了。
Then I thought of the whistle.
接着，我想起了那口哨声。

Of course he must recall the snake before the morning light revealed it to the victim.
当然，天一亮他就必须把蛇召唤回去，以免他想要谋害的人看到它。
He had trained it, probably by the use of the milk which we saw, to return to him when summoned.
他训练那条蛇能一听到召唤就回到他那里，很可能就是用我们见到的牛奶。
He would put it through this ventilator at the hour that he thought best,
他会在他认为最合适的时候把蛇送过通气孔，
with the certainty that it would crawl down the rope and land on the bed.
确信它会顺着绳子爬到床上。
It might or might not bite the occupant,
蛇也许会咬，也许不会咬床上的人，
perhaps she might escape every night for a week, but sooner or later she must fall a victim.
她也许有可能整整一周每天晚上都侥幸免于遭殃，但她迟早是逃不掉的。