In astronomy, a scale of magnitude from one to six denotes the brightness of astar.
Giải chi tiết:
denote = biểu thị, chỉ rõ
A. biểu thị
B. dự đoán
C. tương phản
D. kiểm tra
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.