De or het milieu-inspanning?

The correct Dutch article is:

de milieu-inspanning

Rule Words ending in -ing: almost always de. See the rule

How to use milieu-inspanning

the milieu-inspanningde milieu-inspanning
this milieu-inspanningdeze milieu-inspanning
that milieu-inspanningdie milieu-inspanning
our milieu-inspanningonze milieu-inspanning
your milieu-inspanningjouw milieu-inspanning
every milieu-inspanningelke milieu-inspanning
which milieu-inspanning?welke milieu-inspanning?
a big milieu-inspanning / the big milieu-inspanningeen grote milieu-inspanning, de grote milieu-inspanning