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卡标号为16—25的相应位置上。

 Stephen Hawking, who is the most famous physicist, was born in Britain on January 8^th, 1942. As a child, he was enthusiastic about 16      (design) complicated toys but     17   (fortune), in his twenties, he suffered    18    a disease that was impossible to be cured,     19     was a great challenge for him. However, not only was he positive about the misfortunes     20      eventually he defeated all the obstacles but also he was   21   (absorb) in his research in the universe. In 1988, his best-seller A Brief History of Time was published, 22     which he put forward the idea   23    time itself has a beginning, and that it will have   24   end. In conclusion, he has made outstanding   25   (contribute) to the fields of cosmology and quantum gravity.