Answer:
D. All of the above
Explanation:
Because all of these have something to do with how glaciers are affecting the planet.
Answer:
Never smoke near a place where hydrogen is generated or being used. Remove all possible sources of flame and sparks. Hydrogen should only be generated and used in a well ventilated out door area. Precautions must be taken to remove all possibilities of fire or explosion.
Answer:
A. A scientist investigates a mouse's growth in nature by watching the animal.
A field study is a raw collection of data, typically in the natural habit of the organism; hence why an experiment taken in a lab isn't a field study.