Different fourteen crops were grown 8,600 years ago by some of the world's earliest farmers.
Giải chi tiết:
Different fourteen → Fourteen different. "Fourteen different crops were grown 8,600 years ago by some of the world's earliest farmers." (Mười bốn vụ mùa khác nhau được trồng cách đây 8.600 năm bởi những nông dân đầu tiên trên thế giới.)
Around 150 B.C. the Greek astronomer Hipparchus developed a system to classify stars according to brightness.
Biogas can be utilized for electricity production, cooking, space heating, water heating and process heating.