Drinking water, which is ______ must for any human to survive, has to be stored based

on ______ number of people in the household.

[ ]

A. the; a

B. a; the

C. /; the

D. the; the

市场上买2斤榴莲的价钱可以买6斤苹果，买6斤橙子的价钱可以买3斤榴莲。买苹果、橙子、菠萝各1斤的价钱可以买1斤榴莲。买1斤榴莲的价钱可以买菠萝( )。

A．2斤

B．3斤

C．5斤

D．6斤