Name the two activities on which the earliest human beings were dependent for their sustenance.
Which sector of economy accounted for the highest percentage of India’s total value of exports in 2003-2004?
Name the two metropolitan cities which are the main polluters of river Ganga before it reaches Varanasi.
Give the significance of river St. Lawrence as an inland waterway.
St. Lawrence seaway serves the most important industrial region of USA and Canada.