The right answer is A.
Insecticides are active substances or phytosanitary preparations with the property of killing insects, their larvae and / or their eggs. They are part of the family of pesticides, themselves included in the family of biocides, both of which are regulated in Europe by specific directives.
Some pestiids such as organoclorides are broad-spectrum, ie they act on several insects at the same time (whether they are good or bad).
At the center of the cloud, more weight of the gas molecules are present.
The mass or weight at the center of the cloud increases when the gas molecules group together in a molecular cloud because more gas molecules are present at the center which combines with each other leads to heavier weight of gas molecules. The combination of gas molecules make the center of the molecular cloud denser as compared to other parts of the cloud so we can conclude that increase in mass occur at the center of the cloud.
Learn more: brainly.com/question/24722927
True More people do live in development nations than live in developed nations