Final answer:
Keeping loose papers nearby is a dangerous thing to do when working with flames in the laboratory. It is important to keep the workspace clean and free from potential fire hazards. Other safety measures include wearing insulated gloves and cleaning up the workspace before starting. Therefore, the correct option is A. Keeping loose papers nearby.
Step-by-step explanation:
The dangerous thing to do when working with flames in the laboratory is A. Keeping loose papers nearby.
Keeping loose papers nearby can easily catch fire and increase the risk of larger fires. It is important to keep the workspace clean and free from any potential fire hazards.
Other safety measures include wearing insulated gloves to protect against burns and cleaning up the workspace before starting to minimize the risk of accidents.