Tracy and eric are timing how fast marbles roll down an inclined plane. they plan to do this 5 times, and then take the average time for their results. what would be best way to improve the accuracy of their data?

a. include marbles of three different colors in their investigation
b. include the average of 20 trials down the inclined plane.
c. use marbles of 10 different marbles
d. use toy cars instead of marbles

the answer is a

explanation:

the  equal rights amendment  (era) states: "equality  of  rights  under the law shall not be denied or abridged by the united states or by any state on account of sex." congress first introduced the era in 1923, but the campaign for ratification took off in the 1960s during the  civil rightsmovement.

(d) take jobs from american workers.

polticians and sentates thought to annoucne the fialre of articles of confedartion by making a centralized nation as a hole