Read and fill in each of the blanks with one word to complete the passage

Vll. Read and fill in each of the blanks with ONE WORD to complete the passage.
It is extremely cold on Mars, so it is (31)possible to live on this planet right now. There is no liquid water on Mars - just ice. There is also not enough oxygen. on Mars, the average temperature (32) degrees Celsius. Therefore, one of the main goals of making Mars habitable is (33) (34) warm it up. It means that changing the environment Of this planet that it is similar (35) Earth's. One idea for warming Mars a problem on Earth - climate change. Many scientists agree comes (36) that Earth is becoming warmer due (37) increased levels of greenhouse gases in our atmosphere. We might create similar conditions on Mars (38) building factories that release greenhouse gases. These gases will change the atmosphere on this planet. Rain will fall, and it may be possible to grow plants for food. The plants will add more oxygen (39) the air. However, we will have considerable difficulty (40) making Mars habitable. The project could take many centuries, and the cost will be high