It’s quite me why such things have been allowed to happen.
This novel is set in the modern city, San Francisco, so once _______, it will be very popular.
―What can I do for you?―I'd like to buy a present for my son, ________ at a proper price but of great use.
A long time ________ a person, which is really a truth.
five minutes before the last bus left, we arrived at the station.
________ is known to us is that time is limited and precious.