Time should be made use ______ meaningful things.

The young man comes from a(n) ________ family，who owns several companies in London and Paris.　　　　　　　　　　　　　　　　　　　

If a student ____ in the exam, he won’t escape punishment.

As a businessman, Mr. Green is a complete failure. Being lazy may well be one of the______to his success.

I ________ an old friend in the street the other day whose changes surprised me a lot.