The house built of stone lasts longer than ____ built of wood.

—Do you think playing cards is beneficial to our study?—No，if ________，it can help us kill time when we have nothing to do.

 My visit to your school is really an unforgettable experience,         I will always treasure.

— Which would you like, Mary, tea or coffee?— ________ is OK. I am thirsty now.

Surely the day you are informed of your being admitted to a famous key university will be ________ of joy and celebration for your family, relatives and friends.