# Now

This word is used here to mark a stop in the main story.

# a certain Jew named Apollos

The phrase "a certain" indicates that Luke is introducing a new person in the story. 

# an Alexandrian by birth

"a man who was born in the city of Alexandria." This was a city in Egypt on the north coast of Africa.

# eloquent in speech

"a good speaker"

# mighty in the scriptures

"he knew the scriptures thoroughly." He understood the Old Testament writings well.