Question

Identify the topic sentence:
The heart weighs approximately 11 ounces and is as big as a clenched fist. The heart of a man beats about 60 to 80 times a minute and about 40 million times a year. With each beat, it takes in nearly a quarter of a pint of blood; in the course of a single day, it pumps 2,200 gallons of blood, and in a single lifetime about 56 million gallons. What other engine is capable of performing such heavy work over such a long period of time without needing repairs? Without a doubt, the human heart is a small yet highly efficient piece of equipment.

• A. The heart of a man beats about 60 to 80 times a minute and about 40 million times a year.
• B. Without a doubt, the human heart is a small yet highly efficient piece of equipment.
• C. The heart weighs approximately 11 ounces and is as big as a clenched fist.
• D. What other engine is capable of performing such heavy work over such a long period of time without needing repairs?

Answer 1

Answer: (B)

Without a doubt, the human heart is a small yet highly efficient piece of equipment.

The correct topic sentence is Option B as it depicts the size and the importantance of the heart in brief. The main role of a topic sentence is to depict the overall idea of the paragraph in brief and Option B does it appropriately. Options A and C are incorrect as each one of them is only describing one feature of the heart at a time and thus does not summarize the idea in a sentence. Option D is incorrect as it is a question and it actually functions to introduce the topic sentence.