سوال ۱۱ کنکور ارشد ریاضی ۱۴۰۰

PART B: Cloze Test — Read the passage and decide which choice best fits the space.

For some time now, medical scientists have noted an alarming increase in diseases of the heart and circulation among people who smoke cigarettes. (11) __________ in the bloodstream causes blood vessels to contract, thus (12) __________ circulation, which eventually leads to hardening of the arteries. (13) __________ the arteries stiffen, less blood reaches the brain, and the end result of this slowdown is a cerebral hemorrhage, commonly (14) __________ to as a "stroke". In addition, (15) __________ reduces the ability of the hemoglobin to release oxygen, resulting in shortness of breath.

11 — Which choice best fits blank (11)?