Which of the following observations indicates that conditions on mars may have been suitable for life in the past? mars has two small moons. there are very large extinct volcanoes on mars. there are dried-up riverbeds on mars. there is a very deep and long canyon that extends across mars. mars has polar caps made of "dry ice."

Which statements describe sustainable development? multiple answer choice -fishing does not remove more fish from water systems than can be replaced by the number of fish that will be born to replace them. -sustainable development is development that is designed to improve the economic conditions in less-developed countries. -sustainable development is mainly a regional issue. -sustainable development means water is used at a rate that won't reduce the amount available for future use. - sustainable development policies only need to be concerned with environmental protection. - trees cannot be cut down faster than the number that will be replaced by new growth.