A tennis racket needs to be both strong and stiff. But it also needs to be lightweight. Tennis rackets can be made of a number of different materials. The graphs below show some of the advantages and disadvantages of different materials that are used in tennis racket frames. Use the graphs to answer the following question.

Which system revise and send electrical signals throughout the body

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h,o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain