Once ice forms on a lake in winter, the water underneath the ice remains about 4 c even if the air temperature just above the ice far below freezing. What property of water helps keep the water below the ice from freezing?

Explain why biological control methods are generally environmentally superior to chemical pest control methods.

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit

What type of graph presents information about how often certain or traits occur?