Write the Topic Sentence of Each Paragraph

Write the topic sentence of each paragraph.
Located at the front of the neck, the thyroid gland produces hormones that control metabolism.If the thyroid becomes under or overactive, it can cause some serious problems.Should the thyroid become overactive, the body responds with a number of symptoms.Diarrhea, heat intolerance, anxiety, palpitations, and weight loss are just a few of the symptoms resulting from an overactive thyroid gland.However, an underactive thyroid also causes unpleasant and sometimes serious side effects.Fatigue, depression, dry skin, unusual sensitivity to cold, and hair loss are some of the symptoms that can occur when the thyroid is underactive.