they felt h________that they could do something for a better environment

they felt h________that they could do something for a better environment
they felt h________that they could do something for a better environment

they felt h________that they could do something for a better environment
happy
他们能为改善环境做些事,他们感到很高兴

happy

HAPPY 把Fell smell sound touch 当系动词用，后面跟名词