问题补充:
seems to be one of the main reasons for many people in today’s world.
A. Having an adventure; to travel
B. To have an adventure; traveling
C. Have an adventure; to travel
D. To give an adventure; traveling
答案:
(答案→)A. Having an adventure; to travel
B. To have an adventure; traveling
C. Have an adventure; to travel
D. To give an adventure; traveling
解析:seems to be one of the main reasons for many people句中缺少主语,排除C;而不定式作主语表示具体的一次行为,本句是泛指冒险这一行为,所以也排除B和D。选A。