I thought _______ very useful to know the customs of foreign countries.

—What a lovely card! Where did you buy it? —I made it by _______.

Have you returned the book to the library ____?         --- Yes, I have ____ returned it.

The shoes are neither cheap nor comfortable, I can’t understand _______women like buying them . 

— ________ does your mother go to work in the morning?— She always goes to work at seven o’clock.