Also, anthropologists speculate that the relative helplessness of human children has made multiple caregivers a vital necessity - that encourages bringing dad into the picture.
此外,人类学家推测,人类儿童的相对无助使得他们极其需要众多的照顾者——促使父亲也加入进来。
3
However, at times of high vector densities the relative importance of mosquito-to-human transmission may increase.