Sentence 1: Randy was mixing several chemicals together. 
 Sentence 3: The test cubes ended up on the ground 
 Sentence 4:  The teacher told everyone to move away from the puddle 
 Sentence 5:  He took out a cleaning kit and cleaned the spill 
 Option 1: He caused a fire in the laboratory. 
 Option 2: He slipped on a small amount of water on the floor.