30 m/hrs (add me on discord if u have it Sipstic++#1460 )
Answer:
let's go to the beach or u will relax lol

Blank # 1 - keep safe distance from the burner
Blank # 2 - Place the equipments on the right place after use
Blank # 3 - perform experiments with proper lab equipment and safety tools
Blank # 4 - Don't break any test tube or lab equipment
(maybe it can be hazardous)
B I think is right. Hope this helps!