Кто по шарит

choose the correct variant of the preposition. task (0) is an example.
a) for b) in c) on d) of
0. our growing need for food has had many harmful effects on the environment.
1. scientists study the long-term consequences of human actions the environment.
2. to understand influence the earth, the nasa began to use satellites to study global warming.
3. even minute changes any one factor in an ecosystem can change a particular plant or animal.