21.   Developing the technology for sustaining human life there and getting Earthlings home again safely could take years.

22.   Families will have to accept that feeding cannot sustain life in the face of terminal diseases.

23.   Her feeding tube is not extraordinary life support, not a futile gesture to sustain a life already lost.

24.   High-rise buildings are important to cities and in sustaining lives, Katz said.

25.   How much longer will the Sun sustain life on Earth?

26.   In as little as five years, he said, it could become too salty to sustain life.

27.   Indeed, this desert, despite averaging less than two inches of rain annually, sustains life in many forms.

28.   It would carry enough oxygen to sustain life, and if it were chilled, it would cool the blood via the vast network of capillaries in the lungs.

29.   Its voluminous waters supply vital elements that sustain life on the surface and regulate planetary heat flow, keeping the land temperate.

30.   Like oxygen, it is a gas needed to sustain life on this planet.