Na convection cycle, what causes plastic-like material to sink a. it loses heat to the crust. b. it gains heat from the crust. c. it loses heat to the outer core. d. it gains heat from the outer core.

Me ! which of the following is an environmental concern of genetically modified foods? a) crops that are drought resistant are introduced providing food regardless of the unpredictable weather b) reduction cost of production for the crops c) an important ingredient may be introduced in a strain of rice for the poor who depend on rice as a primary food d) toxic substances produced as a pesticide may be consumed by unintended species