A trip to the ocean can be a relaxing escape from the everyday pressures of life. A sailboat glistening on the horizon provides a mental escape to faraway places. The rhythm of the ocean beating against the sand is sedating music to a troubled mind. A slow, gentle breeze can relax your tensions. You should always be careful to avoid overexposure to the sun at the bea ch.

This question is incomplete. I've found the complete question online. It is as follows:

Answer each of the following questions according to the instructions given. Question 1 (a–b) is based on the following paragraph.  

A trip to the ocean can be a relaxing escape from the everyday pressures of life. A sailboat glistening on the horizon provides a mental escape to faraway places. The rhythm of the ocean beating against the sand is sedating music to a troubled mind. A slow, gentle breeze can relax your tensions. You should always be careful to avoid overexposure to the sun at the beach.  

1.a. Write the sentence that is the topic sentence of the paragraph.

1.b. Write the sentence that is unrelated to the topic and can be eliminated.

Answer and explanation:

1.a. Write the sentence that is the topic sentence of the paragraph.

The topic sentence is the very first sentence "A trip to the ocean can be a relaxing escape from the everyday pressures of life."  

The topic sentence of a paragraph is supposed to express its main idea. It works as if it is a map that allows readers to know where the author is going, what idea is guiding the author. In the paragraph we are analyzing here, particularly, the author is clearly talking about relaxation, and how the ocean help us rest and relax.

1.b.  Write the sentence that is unrelated to the topic and can be eliminated.

The sentence that is unrelated to the topic and can be eliminated is the last one, "You should always be careful to avoid overexposure to the sun at the beach." The paragraph, as we noted before, has relaxation as its topic, as the main idea. The purpose of the paragraph is not to advise people on the perils of overexposure to the sun. It is to unveil how relaxing going to the beach is. Therefore, that sentence does not help develop the topic, even if it is useful as a piece of advice.

i go to the store and buy some cheese,suddenly there was akward silence.   out of no where comes a ninja, and he takes an apple, and chokes the cashier, until he passes out.   the disapeared in a puff of smoke.   the cashier went to the doctor, and everything was fine again.   they all lived happily ever after without anymore ninjas.

the end

go to buy cheese= exposition

akaward silence= rising action

ninja chokes the cashier= climax

cashier goes to the doctor= falling action

they live happily ever after= resolution