The angel Gabriel was sent by God, to a city of Galilee named Nazareth, to a virgin betrothed to a man whose name was Joseph, of the house of David; and the name of the virgin was Mary. Upon entering, the Angel said to her “Hail, full of grace. The Lord is with you. Blessed are you among women.” When she had heard this, she was disturbed by his words, and she considered what kind of greeting this might be.
The Angel said to her “Do not be afraid, Mary, for you have found grace with God. Behold, you shall conceive in your womb, and you shall bear a son, and you shall call his name JESUS.” (...) Then Mary said to the Angel: “How can this be, since I am a virgin?” “The Holy Spirit will come upon you, and the power of the Most High will overshadow you. And because of this also, the Holy One who will be born of you shall be called the Son of God.” (...)
Then Mary said “Behold, I am the handmaid of the Lord. Let it be done to me according to your word.” And the angel departed from her.
Quote taken from "Public Domain Catholic Bible"