Resposta:
A. The Earth's average temperature has increased dramatically over the last decades. (Increase)
B. Hot and very hot days have become more frequent.
C. Deforestation has caused many species to disappear.
Explicação:
O Present Perfect de qualquer verbo é composto por dois elementos: o verbo auxiliar have (no presente) e o past participle (passado particípio) do verbo principal.
Obs.: Has é a conjugação do verbo Have nos pronomes She, He e It.
Estrutura Present Perfect na forma afirmativa:
Sujeito + Verbo have/has + verbo principal do Past Participle + complemento
Ex:
She has traveled to London.
Estrutura Present Perfect na forma negativa:
Na forma negativa, basta adicionar not logo após o verbo auxiliar have.
Sujeito + Verbo have/has + not + verbo principal do Past Participle + complemento
Ex:
She hasn't traveled to London.
Obs.: É bem comum o uso de have e not na forma contraída:
Have + not = haven't
Has + not = hasn't
