One should not trust a source if the authorship is hidden. true // false

active voice: my father cut the tree.

passive voice: the tree was cut by my father.

active voice: people buy newspapers every day.

passive voice: newspapers are bought (by people) every day.

active voice: people have been using movies as political propaganda since world war ii.

passive voice: movies have been used as political propaganda since world war ii.

active voice: donna gave me my birthday present.

passive voice: i was given my birthday present (by donna). / my birthday present was given to me (by donna).

active voice: mom will leave the keys on the counter.

passive voice: the keys will be left (by mom) on the counter.

the words in parentheses are the agent of the passive voice and can be omitted when obvious, generic, or simply unnecessary.

i decided to stay late in the laboratory to continue my experiment with the lightbulb. at midnight, thomas edison opened the door and saw all the stuff he was working on. the lightbulb, film and the transmitter. as he walks in an idea hits him on how the lightbulb would work. he would have to change a few wires around to get it to light up. when he did change the wires around it worked so he decided to write a telegraph to his friend to tell him about his success.   as he was packing up he grabbed the telegraph and walked to his home. he told his wife about the success and the next morning mailed the telegraph.