The time he has devoted in the past years ______ the disabled is now considered ______ of great value.
______ the secret of nature, the young scientist has little time for entertainment.
_________ into a famous university made his parents very happy.
________the working efficiency, the boss allows the employees to have a coffee break.
Only when he read this novel for a second time ________ to appreciate its beauty.
I ________ the boy to save the money, but he would not listen to me.