1. How does nature form a danger to people in the world and how can science help reduce that threat. 大自然是怎样对全世界人民形成一种威胁的及科学能如何帮助减少这种威胁。( p.73 Warming Up No.3)
1) danger此处用作可数名词，意为“危害，威胁”，常与介词to或of连用。如：① The narrow bridge is a danger to traffic. 这座狭窄的桥梁对交通造成了危险
