تست های کنکوری درک مطلب زبان انگلیسی (3) دوازدهم | درس 3
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

Energy is the ability to do work. It can take a variety of forms:mechanical, electrical, chemical, and nuclear. To produce any type of energy, the resources of the earth are used. The main resources of the earth are fossil fuels such as natural gas, oil, and coal.
Which of the followings hasn't been mentioned in the paragraph?