One possible explanation for past climate changes is the movement of earth’s major cities from their previous positions.
a. true
b. false

Describe the primary and secondary immune response in terms of speed and number of antibodies produced?

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Which ideas did your answer contain? check all that apply. no food for organisms no oxygen in the atmosphere no trees or flowering plants no products based on trees or plants (building materials, medicines, fuels, fibers) no fossil fuels