Brainwashed! This bible says that the writers of the new covenant were quoting the Greek Septuagint!

The mesoretic text was destroyed by the Romans in yerusalem but copies of the mesoretic text still exist and the dead sea scrolls.

Why would Hebrew people use the Greek translation of the old covenants to write the new covenant?

The new covenant was written in the Aramaic Peshitta in 50-70AD in Aramaic, before the Greek new covenant existed.

in the beginning of the world there was Greek or Hebrew?

The Hebrew bible that was in the temple in yerusalem until 70AD when the Romans destroyed it. The same time Timothy delivered the Aramaic Peshitta to the church of the east surviving the Romans so that the new covenant is preserved in Aramaic before the Greek new covenant was written.