1·Venomous snakes spit and hiss when they are cornered.
毒蛇在无法逃脱时会发出愤怒的呼呼咝咝的声音。
—— 《牛津词典》
2·Probably back in some previous biology course you learned that snakes evolved from lizards, and that the first snakes weren't venomous and then along came more advanced snakes, the venomous snakes.
也许在以前的生物课上，你学过蛇是由蜥蜴进化而来的，而且最初的蛇是没有毒的，后来出现了更高级的蛇，也就是毒蛇。
3·Ok, venomous snakes are the ones that secrete poisonous substances or venom, like the snakes of the viper family or cobras.
毒蛇是一种分泌有毒物质或毒液的动物，像蝰蛇科的蛇或眼镜蛇。
4·They are classified as venomous snakes because they resemble them, their advanced features more than the other non-venomous snakes.
它们被归类为毒蛇，因为它们与毒蛇相似，它们的高级特征比其他不是毒蛇的蛇更明显。
5·Colubrids, and you probably heard this too, although they are often classified as venomous snakes, they are actually generally non-venomous.
黄颌蛇，你可能也听过这种蛇，虽然它们经常被归类为毒蛇，但实际上它们通常是无毒的。
6·If there are no truly non-venomous snakes, were the so-called non-venomous snakes, like constrictors and pythons, were they venomous at some point in their evolution?
如果没有真正的无毒蛇，那些所谓的无毒蛇，比如蟒蛇和巨蟒，在它们进化过程中的某个阶段是有毒的吗？
7·In most venomous snakes, like vipers and cobras, the venom is used to catch and inmoblize the prey; but in colubrids, venom drips onto the prey only after the prey is in the snake's mouth.
在大多数毒蛇中，如蝰蛇和眼镜蛇，毒液用于捕捉猎物、使其无法行动；但在彩颌类中，只有在猎物到了蛇嘴里后，毒液才会滴到猎物身上。
8·Or you may dream of tigers and venomous snakes.
或梦者到老虎、毒蛇。
9·An American set a record in 1999 kissing 11 venomous snakes.
1999年，一名美国人曾创下与剧毒蛇亲吻11次的记录。
10·We kept a vigilant eye out for alligators and for venomous snakes.
我们警惕地睁大眼睛，以防短吻鳄和毒蛇的出现。