Answer – C (Using instruments that have not been calibrated).
When the integrity of an instrument’s calibration has been compromised (usually due to exposure to a shock, vibration, or physical damage), it needs to be calibrated; failure to do this inevitably leads to inaccurate measurement; this is a very common measurement error.
The pollutants in 1970 were the highest since recorded history and are declining steadily.
Answer:
I think it would be grass.
Explanation:
I am pretty sure it would be grass because there is much more grass on earth then hawks, snakes, and rabbits.