In the 1980s the northeast region of brazil received almost no precipitation for how many years?

3 years

Explanation:

Even there was  a dry year in 1979, the area received almost the normal amount of rain in 1980.

In 1981 however, the year was quite dry, with rainfalls in drop of almost 20%, that began one of the most important drought in the history of Brazil.

In 1982, rainfalls were down by 30% and it got even worse.

In 1983, the rainfalls were down by about 35%, essentially destroying all the agriculture system that had been severely damaged by the two previous years.

In 1984, rain came back a bit higher than its traditional levels, and in 1985, the area was flooded by rain surpassing the average by 60%!

2. this rock sample is limestone and shale. with what you know about rock formation, what type of environment did these organisms live in?