Question

5) Read the text: The water we drink The water we drink usually comes from reservoirs. Lakes, or rivers. A large number of cities use river water and dumps it back into the river. Sometimes another city downstream uses the same water. This water may be badly polluted with chemicals and pathogenic bacteria. Many different chemical treatments are necessary to make it safe palatable. Many communities add some form of fluorine to their water, fluorine in concentrations of 0.7 to 1.0 ppm (parts per million) can significantly reduce tooth decay in children. Smaller communities usually obtain water from wells. Even they have problems because sometimes the ground water is contaminated by nitrates. These nitrates come from agricultural fertilizers and from the decomposition of organic waste. What can we do? We can fight for clear water and convince our neighbors to do the same. We can demand an end to water pollution by industries and cities. And, finally, we must know how to use the water of the earth because that is all the water we have. Choose the correct alternative according to the text.

Many communities add: a) fertilizers to their water.c) fluorine to their water b) organic waste to their water. d) nitrates to their water​

Answer 1

Resposta:

Alternativa c)

Espero ter ajudado,

Bons estudos!