问题详情

According to the passage, ______.
A．we should not worry about the transition of the Earth"s magnetic field
B．the Earth"s magnetic field will not change for at least 2 000 years
C．the Earth"s magnetic field has decreased its strength rapidly
D．the transition of the Earth"s magnetic field can be controlled by modern science请帮忙给出正确答案和分析，谢谢！