Vertebrate animals are organisms that have a spinal column and use bones to support their weight. Scientists consider bones to be an organ of the skeletal system. What organ of a plant is most similar to a bone in animals. A. Stem
B. Root system
C. Cell wall
D. Phloem

You have trained year for a marathon. in your first attempt to run a marathon, you decide that you want to complete this 26-mile race in 4-5 hours. a. what is the length of a marathon in kilometers (1mile= 1.6 kilometers). b. what would your average speed have to be to complete the race 4.5 hours? give your answer in kilometers per hour.