Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.
As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast lane" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.
Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a reduction of blood flow to the heart, may all contribute to the higher incidence of heart attacks between the hours of 8:00 A.M. and 10:00 A.M.
In other studies, both birthdays and bachelorhood have been implicated as risk factors. Statistics reveal that heart attack rates increase significantly for both females and males in the few days immediately preceding and following their birthdays. And unmarried men are more at risk for heart attacks than their married counterparts. Though stress is thought to be linked in some way to all of the aforementioned risk factors, intense research continues in the hope of further comprehending why and how heart failure is triggered.
What does the passage mainly discuss?
A. risk factors in heart attacks
B. seasonal and temporal patterns of heart attacks
C. cardiology in the 1980s
D. diet and stress as factors in heart attacks
Chọn đáp án A
Đoạn văn đang nói đến điều gì?
A. những tác nhân gây đột quỵ
B. tính thời gian và theo mùa của bệnh đột quỵ.
C. nghiên cứu về bệnh tim vào những năm 1980.
D. chế độ ăn và áp lực là nhân tốc gây đột quỵ.
Giải thích: Mở đầu, tác giả nói “As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks” (Khi bệnh tim là kẻ giết người số một ở Hoa Kỳ, nhà nghiên cứu đã ngày càng quan tâm tới việc xác định yếu tố rủi ro có thể xảy ra gây ra cơn đau tim). Sau đó, những đoạn dưới, tác giả nêu ra một vài lí do như bệnh tim, sinh nhật hay độc thân đều là nguyên nhân dẫn đến đột quỵ.