彼は今、手術室で手術を受けています。
Kare wa ima, shujutsushitsu de shujutsu o ukete imasu.
He is currently undergoing surgery in the operating room.
手術室に入る前は、清潔な服に着替えます。
Shujutsushitsu ni hairu mae wa, seiketsuna fuku ni kigaemasu.
Before entering the operating room, I change into clean clothes.