Workers in the united states take an average of thirteen days of vacation a year in italy they take forty-two. what is best way to write this?

1)a

2 b

3 d

4 d or b

explanation:

i think it is b. hope this !

a constant variable, normally called a controlled variable, is the term for a variable that remains constant throughout an experiment, though other variables may change. an example is the water pressure for a faucet when measuring the amount of water released when the faucet is opened to various increments.