单选题 Major life changes may play a role in as many as a quarter of chronic daily headache cases that arise among otherwise healthy adult men and women, study findings suggest. "Major life events may precipitate or co-occur with the development of chronic daily headaches," Dr. Ann I. Scher said. Major life changes literally shake up our world, and invite or pressure us to interact with life in new ways. To grow, we need to change our belief systems to allow for new levels of thinking and performance.
Scher, of Uniformed Services University, in Bethesda, Maryland, and colleagues assessed re ports of major life changes among 206 men and women who met criteria for chronic daily headache (180 or more headache days per year). They assessed similar reports from 507 men and women with "episodic" headache (2 to 104 headache days per year).
The investigators assessed changes in work, marital status, children's status, or residence; as well as deaths of family or close friends. They also inquired about self-defined "extremely stressful situations," such as financial problems, an ongoing individual illness or that of a family member, or an ongoing abusive relationship. Compared with men and women with episodic headache, men and women with chronic daily headache were more likely to have experienced major life events in the 2-year period prior to the onset of their headache condition, the researchers report in the medical journal Cephalalgia.
The strongest predictor of chronic daily headache was an ongoing extremely stressful situation. The researchers also noted a higher proportion of chronic daily headache among people 40 years and older. In this group, "a change in work status was related to increased risk for chronic daily headache, while in contrast, those younger than 40 years showed a decreased risk for chronic daily headache after a job change," Scher told Reuters Health.
These findings are generally consistent with prior research related to other chronic pain conditions, the investigators note. "Our finding that the relationship may be stronger for those older than 40 was an interesting, but secondary, finding that should be replicated in other samples," Scher said.

单选题 What does the word "precipitate" most probably mean?

【正确答案】 A

【答案解析】[解析] 词义题；我们首先在原文中找到包含这个目标词的句子“Major life events may precipitate or co-occur with the development of chronic daily headaches”，这里所讲述的生活中的重大变故和经常性头痛之间的关系在文章的开头就有表述，“Major life changes may play a role in as many as a quarter of chronic daily headache cases”。既然前者对后者发挥重要作用，那么这里的precipitate用A选项来解释是最恰当的。

单选题 From the passage, we know that chronic daily headache refers to______.

单选题 What is the most important difference between those with chronic daily headache and with episodic headache?

【正确答案】 B

【答案解析】[解析] 细节题；符合比较与对比的出题原则，在原文中我们可以找到“Compared with men and women with episodic headache”这样的信息点，所以我们需要的原文信息是“men and women with chronic daily headache were more likely to have experienced major life events in the 2-year period prior to the onset of their headache condition”，比较阅读4个选项，B选项是正确的。