Climatic variations and Human activities , i don’t know the third reason ..
D. BREAD because it is a CARBOHYDRATE (which can be bricked down to energy for your body for later)
<span>The correct option is C. The atmosphere is defined as the envelope of gases that surround the earth. The atmosphere is made up of nitrogen, oxygen, argon and other gases. The nitrogen has the highest percentage composition of 78%. The atmosphere is divided into five layers, the layer that is most close to the earth is called troposphere.</span><span />
A natural resource that is limited in supply