The answer is Neolithic or the New Stone Age. The Neolithic period is known for the spread of agriculture, used of stone tools and also the time where the cereal cultivation for agriculture and animal domestication were introduce and lastly the appearance of pottery is also known as a symbol during this time.
Answer: Ecosystem Services
Explanation: Simply put,Ecosystem services refer to all the benefits that man enjoys from his relationship with the ecosystem.Ecosystem services are the benefits that people obtain from ecosystems. Ecosystem services are indispensable to the wellbeing of all people, everywhere in the world. They include provision,regulation and cultural services that directly affect people, and supporting services needed to maintain the other services. From the availability of adequate food and water, to disease regulation of vectors, pests, and pathogens, human health and well-being depends on these services and conditions from the natural environment.
We depend on nature for our survival – without healthy ecosystems, our drinking water isn’t clean nor is the air we breathe. Studies also show that people who spend time in nature tend to be happier than those that don’t. Being outdoor can even act as a natural anti-depressant. With industry and urban sprawl expanding at unprecedented rates, Ecosystem Services attempt to translate the benefits we receive from nature into economic terms so we can better understand the compromise we are making between nature and industrial development.
I believe the answer is C.
Answer;
-B3
Explanation;
Refrigerants are divided into two groups according to toxicity:
-Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm; and
-Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.
They are also divided into three groups according to flammability:
-Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;
-Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;
-Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.
-Therefore; the answer for the above question would be Class B and class 3.