sentences: a solution is formed by one substance being dissolved in another substance & an astronomers is formed by one or more mountain combined together physically ->  a solution is a mixture  sugar dissolves in water when they are combined & land is a mean of bark & sugar is a kind of pure substance -> sugar dissolving in water is an example of one substance dissolving in another substance sugar dissolving in water is an example of one substance dissolving in another substance  sugar dissolving in water is an example of one substance dissolving in another substance & a solution is formed by one substance being dissolved in another substance -> salt land is a mean of problem sugar water is a kind of solution  a solution is a mixture & salt land is a mean of problem -> sugar water is a mixture