What is an expression of Dalton's law (k = constant)?

When the volume and number of particles of a gas are constant which of the following is also constant

Between 2014 and 2016, more than 25,000 children in flint, michigan, drank water that was contaminated with lead from lead pipes. during this time, the city claimed the water was safe to drink. which of these actions could the city have taken to ensure that the drinking water was free from lead?

There is a single path for electrons. the current decreases when additional resistors are added. the current will be the same in each resistor. these statements best describe a(n) circuit.