In the following passage, some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each blank.

The first human beings to control fire gradually learned (1)______ many uses. Not only did they (2)______ fire to keep warm and cook their food; they (3)______ learned to use it in hunting or warfare, to kill insects, to (4)______ berries, and to clear forests of underbrush so that game (5)______ be better seen and hunted. Eventually they learned that the burning of brush produced better grasslands and therefore more game.

Q:

Select the most appropriate option to fill in blank number 1.

• 1
  its
• 2
  his
• 3
  your
• 4
  their