点击下方单词,选择对的这个单词
1. 无脊椎动物An invertebrate is a creature that does not have a spine, for example an insect, a worm, or an octopus.
1. any animal lacking a backbone or notochordthe term is not used as a scientific classification
多通过句子记忆单词,而不是单独死记硬背。