If you were able to go to the top of a tall building and simultaneously drop an orange and a baseball, they would both hit the ground at about the
same instant because

the acceleration of gravity

Explanation:

If there is no air resistance, or the same amount of air resistance, then objects of the same mass will fall at the same rate.

Gravity.

Explanation:

The orange and baseball would hit the ground at the same time because gravity is pushing it down.

to eliminate ambiguous remote or broad reference it is necessary to focus on anaphoric reference. by definition "anaphoric reference means that a word in a text refers back to other ideas in the text for its meaning." the references should be clear and leave no room for ambiguity.

in the first case the pronoun it probably refers to the car but it has not been mentioned before so we should replace it for the car. in doing so the statement becomes clear.

in sentence number   two   the pronoun he refers to charles dickens the author. yet, the first half of the sentence is about the book a tale of two cities. to repair this it would be better to rephrase the first half : after i read   a tale of two cities by dickens, he so as to remove the remote reference.