Battery-operated slippers are used ______ seeing inthe dark.

________ that China has the largest population in the world

One evening, I was with my friend Auguste Dupin at his house in Paris when he had a visit _____ Georges Godinot, head of the Paris Police

Since the new director took office, we have worked ___hours, －that is to say, we work more freely.

_______ I met him, he was working as a secretary in a big company.