sentence2_structure: Environmental changes<>is<>most responsible for the extinction of most species of plants and animals$$$plants and animals<>have lived<>on earth
sentence1: All these processes result in greater environmental impacts, such as deforestation, soil erosion, extinction of plant and animal species, and pollution.
sentence2: Environmental changes is most responsible for the extinction of most species of plants and animals that have lived on earth.
question: What process is most responsible for the extinction of most species of plants and animals that have lived on Earth?