Rewrite the sentences in the passive. 1. Rainforests regulate the Earth`s weather. 2. Scientists have investigated only

1. Earth\'s weather is regulated by rain forests. 2. Only 2 percent of 250000 plant species is known for their possible medical value. 3. The survival of the ecosystem is constantly proved by developing projects environmentalists. 4. Tougher environmental laws will be needed to be passed by governments and elected officials. 5. The Hawaiian monk seal is nearly driven to extinction by the oil explosion business. 6. The environment was protected by Greenpeace long before it became fashionable 7. Blue whale was hunted by whalers almost to extinction.