Space, is what i would guess.
I think the answer is naturally acquired active immunity..also depends on which disease
Answer= Because polar bears depend on ice as a habitat to survive the more the temperature is rising and the sea ice melting as a result of global warming there is basically a possibility that the population of polar bears will decline because there will be no home (habitat)left for them to breed(survive)in.
True. Especially if you are a visual learner. The models help explain the world in a easier way. Words is another method teachers and people use. But models make it fun and more understanding
