Which two statements about composite materials is true? A. They're made up of more than one substance

B. They have the same or similar properties as the materials used to make them

C. They're always made of metal

D. They're readily available in nature

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Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

Lab reagent, hypothesis test.a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl.these six measurements are assumed to be an srs of all possible measurements from solution.they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution.carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

20 pts ‼️ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraft’s weight the greatest?