It’s not until you have lost your health _______ you always take for granted _____ you know its value.

Suan!Where have you been? You have no idea ___ worried I was.

It’s difficult to calculate       its price would be if the museum wanted to sell the ancient vase.

______is known to us, he is the top student of our class.

Peter was so excited __________ he received an invitation from his friend to visit them.