Adolescence /ˌæd

It is doubtful whether/if they ever reached the summit before they died.
It was doubtful that the money would ever be found again.
environmental /ɪnˌvaɪ ə  .rə n  .ˈmen.t ə l/ /-ˌvaɪr.ə n  ˈmen.t ̬ ə l/ adjective
relating to the environment
People are becoming far more aware of environmental issues .
environmentally /ɪnˌvaɪ ə  .rə n  ˈmen.t ə l.i/ /-ˌvaɪr.ə n  ˈmen.t ̬ ə l-/ adverb
environmentally damaging chemicals industries which work in an environmentally responsible way
environmentally sensitive areas
environ mentally friendly adjective
not harmful to the environment environmentally-friendly washing powder
feasible /ˈfiː.zə.bl ̩/ adjective slightly formal
1. able to be made, done or achieved
With the extra resources, the scheme now seems feasible.
[ + to infinitive ] It may be feasible to clone human beings, but is it ethical?
2. possible or reasonable