The following passage contains ten errors. Each line contains a maximum of one error. In each case only one word is involved. Proofread the passage and correct it on your answer sheet.
It is indisputable in order to fulfill its many functions, water _51_
should be clean and biologically valuable. The costs
connected with the provision of biologically valuable water
for food production with the maintenance of sufficiently
clean water, however, are primarily production costs. _52_
Purely “environmental” costs seem to be on this respect _53_
only costs connected with the safeguarding of cultural,
recreational and sports functions which the water courses
and reservoirs fulfill both in nature and in humane settlement. _54_
The pollution problems of the atmosphere resemble those
of the water only partly. So far, the supply of air has not
been deficient like was the case with water, and the _55_
dimensions of the air-shed are so vast that a number of
people still hold the opinion that air needs not be _56_
economized. However, scientific forecasts have shown that
the time may be already approaching that clear and _57_
biologically valuable air will become problem No.1.
Air be ubiquitous, people are particularly sensitive about _58_
any reduction in the quality of the atmosphere, the
increased contents of dust and gaseous exhalations, and
particularly about the presence of odors. The demand on _59_
purity of atmosphere, therefore, emanates much more from
the population itself than the specific sectors of the national _60_
economy affected by a polluted or even biologically
aggressive atmosphere.
