a ruler is used for measuring the length of an object & a seashell is a kind of object ->  a ruler can be used for measuring the length of a seashell  a balance is used for measuring the mass of an object & a seashell is a kind of object ->  a balance is used for measuring the mass of a seashell  a ruler can be used for measuring the length of a seashell & a balance is used for measuring the mass of a seashell -> a ruler and balance can be used to measure the length and mass of a seashell