ロックウールでした
rokkūurudeshita
1. It was rock wool.
★ Common
Noun
#234459
1. It was rock wool.
1. pupil; disciple
1. lock
2. lock (in rugby); lock forward
1. rock (music)
2. rock; boulder
3. on the rocks (drink)
1. wool
1. automatic lock
2. automatic door-locking system
1. hard rock
1. becoming a pupil (of); becoming an apprentice
1. deci-; 10^-1
1. rock wool; mineral wool