英语 九年级 填空题 较难 ★ 精品

伟人生平介绍类阅读理解技巧 — 英语填空题

沪教版·英语(初中) Unit 1 Great people AI 三重审校通过

题目
Read the life story. Leo was born in 1950. In 1972, he began to teach science in a small town. He built a low-cost water filter in 1980. In 1985, he started a clean-water project. He won a science prize in 1990. Which event happened immediately before he won the prize? ___