Answer:
Gases in Earth's atmosphere traps the Sun's heat. These are called greenhouse gases.
Explanation:
B
) experiment showed that all cancers can be cured by new drug
The meaning of the scarce is insufficient for demands.
The scarcity of the food is determined by the availability of the food in the market. In case, the food available in the refrigerator is easily available in the nearby stores, then it is not scarce. In case, the food available in the refrigerator is not readily available in the market, then it is scarce.
A true
<span> Before agriculture was developed people mostly were nomadic in nature. They moved from place to place in search of food. Some of them were groups of hunter gatherers as well. When agriculture started people also started to settle down in groups. This led to the development of civilization and in modern day cities and towns. The first agricultural practices were started beside the river banks due to the reason that the soil was very fertile and water for irrigation was also easily available. </span>