De or het longbeschadiging?

The correct Dutch article is:

de longbeschadiging

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

How to use longbeschadiging

the longbeschadigingde longbeschadiging
this longbeschadigingdeze longbeschadiging
that longbeschadigingdie longbeschadiging
our longbeschadigingonze longbeschadiging
your longbeschadigingjouw longbeschadiging
every longbeschadigingelke longbeschadiging
which longbeschadiging?welke longbeschadiging?
a big longbeschadiging / the big longbeschadigingeen grote longbeschadiging, de grote longbeschadiging