Given those answer options, answer the question: Read the following article and answer the question. Article: What will the future be like? What do you think of it? Here are some answers from some students. Roy Burns: I think life in the future will be better. Most people in the world will use "green cars" by 2020, so there will be less pollution and people will live to be 200 years old. As for space travel, I would say, we will travel to Mars and some other stars in about fifty years. Helen Lester: If we don't take good care of the earth now, our children and grandchildren will be born into a world with too much pollution. There will be fewer trees and more buildings, because there will be more people. Kitty Smith: I agree with Helen Lester. Things will be worse. The weather in the future will be much hotter. Human beings will have to look for another _ to live on. Question: Why does Kitty Smith think human beings will have to live on another planet? Answer:
A:
The earth will be too hot to live on.