Задание 1.
1 - d
2 -a
3 - e
4 - b
5 - c
задание 2
1 insects
2 human beings
3 pollute
4 environment
5 prohibited
задание 3
national, ecological, fortunately
задание 4
the russian federation / the largest.... / the alps / the pamirs / the urals / the united kingdom
задание 5
1 what would you do if you were me?
2 if she had not studied better, she would not passed her exams ( в этом не уверена)
3 if people had avoided damaging nature, many species of animals would not disappeared
4 if i finished my reseach, i woild take part in the conference