Here are the answers to your questions based on the information provided:
Question 1:
In which sphere does a dolphin swim?
Answer: hydrosphere
Question 2:
What is the scientific name for the layer of gas that surrounds the Earth?
Answer: atmosphere
Question 3:
What is the major cause of the Earth's magnetic field?
Answer: the Earth's liquid outer core
Question 4:
Which materials are included in the hydrosphere that are not in liquid form?
Answer: ice caps
Question 5:
What is the name of the zone of life on Earth?
Answer: biosphere