Fill in the missing word. Write only the number and the missing word. 3.1 Households are \( \ldots 3.1 .1 \) of the factors of production \( 3.1 .2 \ldots \) are buyers of factors of production which are converted into finished goods and receive \( \ldots 3.1 .3 \) in return. The government collects \( \ldots 3.1 .4 \) from both \( \ldots 3.1 .5 \) and \( \ldots 3.1 .6 \)