Select the correct text in the passage. Erin is writing a paper on the northern lights. In which sentence should she add a definition to help clarify her ideas?
The northern lights are colorful swirls of light that flicker in the nighttime sky in the upper part of the northern hemisphere. This natural
occurrence happens when fast-moving, electrically charged particles (electrons) from space collide with the oxygen and nitrogen gas in our
atmosphere. These electrons originate in the magnetosphere. As they rain into the atmosphere, the electrons give energy to oxygen and
nitrogen molecules, making them excited. When the molecules return to their normal state, they release small bursts of energy in the form of
light.
When billions of these collisions occur and enough photons are released, the oxygen and nitrogen in the atmosphere let out enough light for the
eye to detect it. This ghostly glow can light up the night sky in a dance of colors. But since the northern lights are much dimmer than sunlight,
they cannot be seen from the ground in the daytime.
The color of the northern lights depends on which gas is being excited by the electrons and on how much energy is being exchanged. These
molecules also let out ultraviolet light which can only be detected by special cameras on satellites.

the correct answer can either be a or b because it could be both but you should probally choose b

a complex sentence consists of an independent clause and one or more dependent clauses.  

to write complex sentences, we must use subordinating conjunctions.  

all the complex sentences begin with a subordinating conjunction and when it occurs, a comma must be place at the end of the dependent clause. on the contrary, if the sentence begins with an independent clause, then no comma is used.

after  

although  

as  

because  

before  

if  

since  

when  

for example,  

after she won the competition, she became very popular.  

although my father was hurt, he continued fighting for his rights.  

as all of you got a ten, you will be able to leave early today.  

before he went to the war, he asked his parents to bless him.  

if it is cold, i won’t go out.  

since you didn’t bring the homework, you will get low grades.  

when it is hot in the town, everyone goes to the beach.  

the metamorphosis is based on an evident father-son problem. this story shows, as a result of the unthinkable transformation of the son in an insect, the deformation and destruction of the individual caused by the authoritarian and hierarchical structures of the family. the narrative begins with the transformation into an insect of enormous proportions of the traveling salesman gregor samsa, a lonely, introverted and submissive, who keeps his family with his work. when he worked, he was appreciated by everyone, but, now that he can not work, he is despised, especially by his father, but this is going to be joined, painfully for the protagonist, first his mother and, finally, his own sister, grete, with whom he had held a special relationship of complicity and affection for many years.

condemned by a deep sense of responsibility, gregor fears the reaction that his frightful aspect will incite in his family. he feels guilty for not being able to continue being useful to the beings he maintained. his own family, however, is ashamed and runs away from him, and even tyrannizes and resists him. the father, of a severe and despotic character, humiliates him and treats him with great cruelty. all his attempts to escape from the confinement to which he is subjected in his own room fail before the hostile rejection of the beings that surround him. prisoner in his lair and unable to continue playing the only function of making money he had, finally chooses, with the consent of his parents and sister, to die of starvation. with this, he is freed from a servile and unhappy existence. the family appreciates gregor while he fulfills the interests. but when he is unable to continue earning money, it becomes a problem, a shame, and family relationships begin to become tense, until coexistence becomes impossible.

the story is not posted