It was at 12 o’clock _________ they came home from school.

We learned in geography class that the earth __________around the sun.

I left my old job because my new company __________ me a very good job .

Police now believe that the crime could be ________ to the one which happened last week.

The colors on the national flags can be ______ differently in different culture, but they have one thing in common, that is, ______of the colours was carefully chosen.