How the loans are paid should be of little concern to the bank ________ they are paid on time.[ ]

What does your brother look like —________.

－How was the journey－Tiring! I caught the train at the last second but all the seats _____. I stood all the way.

The computer system broke _____ suddenly while he was searching for information on the Internet.

He _____ in a university for five years, but now he runs a company of his own.