题目

An eighteen-year-old high school student from Utah won the top prize in the Intel Science Talent Search in the United States. The winner received a computer and a scholarship for a college education. The top winner received 100,000 dollars for college. Shannon Babb of American Fork High School studied the water quality of tile Spanish Fork River in Utah for six years. She found that people have a harmful effect on the river through human activity, including agriculture. And she suggested ways to improve the water quality in the future. These include educating the public not to put hou我国是一个人口大国，我国人口的突出特点是A. 人口基数大，人口增长快 B. 人口基数大，人口增长缓慢C. 人口基数小，人口增长缓慢 D. 人口基数小，人口增长快