Task: Sentence Expansion
Input (English): Unlike rodents , which have gnawing incisors that grow throughout life , the teeth of shrews wear down throughout life , and they lose their milk teeth before birth .
Output (English): Whereas rodents have gnawing incisors that grow throughout life , the teeth of shrews wear down throughout life , a problem made more extreme because they lose their milk teeth before birth , so have only one set of teeth throughout their lifetimes .