PLEASE HELP MULTIPLE CHOICE BIO TEST

Which of the following statements is true? 1. the mantle of the earth is made of solid nickel and iron. 2. the crust of the earth is made of solid nickel and iron. 3. the inner core is made of solid nickel and iron.

What was the land like over 500 million years ago? what was under the sea?

Why can cancer in the lymph nodes (lymphoma) be particularly dangerous? a. the lymph node's ability to produce cancer-fighting lymphocytes would be compromised. b. the lymph node's ability to produce cancer-fighting lymph would be compromised. c. the lymph nodes produce lymph, which nourishes growing cancer cells. d. the lymph nodes produce chyle, which nourishes growing cancer cells.