题目内容：

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题纸相应位置上。

A new study looks at air pollution and its effects on premature deaths in the United States. Premature deaths1. (define) as those that take place before the average age of death.

Researchers found that half of all such deaths related to air pollution2. (result) from pollution that came from another state. The study is the first 3.(examine) how pollution crossing state lines affects early deaths .

Worldwide, an4.(estimate) 4.2 million premature deaths are linked to outdoor air pollution. Most of those deaths are from heart disease, stroke and lung disease, as well as acute breathing infections in children.

Efforts to deal with outdoor air pollution have5.(large) centered on relationships between local sources of pollution and local air quality.6.  Barrett and other researchers found that, in the United States, cross-state pollution is a major concern.

The computer model looked at the atmospheric chemistry processes and weather conditions over7.11-year period. The researchers then examined how each of the lower 48 states affects pollution and people's health in every other state.

The team found electric power plants8.release sulfur dioxide (二氧化硫) were the biggest9.(contribute) to deaths related to pollution from other states. In 2005, sulfur dioxide from power plants was involved10.75 percent of cases of premature deaths from out-of-state pollutants.