lifeonotherplanetsFo的甄选

问题详情：Isthereintelligent(有智力的)lifeonotherplanets?Foryears,scientistssaid“no.”or“wedon’tknow.”Buttodaythisischanging.SethShostakandAlexandraBarnettareastronomers(天文学家).Theybelieveintelli...