根据汉语提示,完成句子.即使是科学家也不能确定别的行星上是否有生物存在.Even scientists are not sure ____ _____ ______ living things.拯救全球变暖还为时不晚.It is never ____ _____ ____ _____the earth from thegiobal warning.

问题描述:

根据汉语提示,完成句子.
即使是科学家也不能确定别的行星上是否有生物存在.
Even scientists are not sure ____ _____ ______ living things.
拯救全球变暖还为时不晚.
It is never ____ _____ ____ _____the earth from thegiobal warning.