When were the oil discoveries in Brazil?
When were the huge oil discoveries made in Brazil?
The first half of the 1990's were in the 70's and 1980's.
The first half of the 1990's was in the 70's and 1980's.
Quando foram descobertas imensas de óleo do Terciário/Cretáceo no Brasil?
Quando se fizeram as imensas descobertas de óleo do Terciário/Cretáceo no Brasil?
Nos anos 1970 e 1980 e na primeira metade dos anos 1990
Nos anos 1970 e 1980 e na primeira metade dos anos 1990