It was not forced upon them by the survival competition; they could have caught and lived on prey without using poison, just as the thousands of non-poisonous snakes still do.
毒液不是生存競(jìng)爭(zhēng)強(qiáng)加給它們的,它們也可以不用毒液捕捉動(dòng)物而生存,就像今天成千上萬(wàn)的無(wú)毒蛇那樣。