True: Deep sea drivers carry oxygen cylinder with them., In a dark room dust particles can be seen in the path of light, False: Smoke does not act as a pollutant., Hydrogen acts as a fire extinguisher. , 2. In the absence of oxygen, we can burn LPG. ,

AIR AROUND US 2

リーダーボード

表示スタイル

オプション

テンプレートを切り替える

自動保存: を復元しますか?