Answer:
"Creating more paved surfaces"
Option C will be the answer
The combined mass of rock 1 and 2 = 19.28 + 25.3
= 44.58
Difference between rock 3 and combined rocks
= 46.3 - 44.58
= 1.72 grams
therefore, the third rock was 1.72 grams greater than the combined mass of the other two rocks.
Mouth or nose. Then goes into your trachea and into your lungs
Answer:
An experiment imposes treatment on the subjects, but an observational study does not
Explanation:
Observational studies are research studies in which an effect, process behaviour etc. are observed, without any change. For example, observation of the possible effect of a treatment on subjects.
On the other hand, experimental studies are studies in which the treatment is included. Experimental studies are randomized, meaning that subjects that are in experiment are randomly put to a treated group or a control group.