SORU: aşağıdaki parçaya göre cevaplayınız
It is clear from the passage that in Europe, during the first four decades or so of the 20th century, ----.
In the first half of the 20th century, acid rain - whether
natural or unnatural - was a hidden phenomenon. By
the 1950s, however, its effects were becoming
apparent to scientists in Scandinavia with the loss of
fish from mountain lakes. A network of rainwater
monitoring stations was set up across Europe, which
very soon proved the existence of acid rain as a
result of human activities. Acid rain was also charged
with killing vast tracts of forest in Germany. The
effects of long-range sulphur pollution were looking
so worrying that the issue was placed before the
world at the UN Conference on the Human
Environment in Stockholm in 1972. The outcome
was that states are now responsible for ensuring that
their activities do not damage the environment of
other states. This paved the way for the development
of programmes for reducing long-range air pollution.
The most important of these was the Convention on
Long-Range Transboundary Air Pollution, attended
in 1979 by the world's leading industrial nations.