Please answer this quickly

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 is the surface temperature of the ocean where hurricanes form? greater than 80 celsius approximately 27 celsius at least 76 celsius less than 10.5 celsius

This part insulates the reaction chamber from the transfer of heat to or from the surrounding environment