When I was little, my mother used to sit by my bed, ______ me stories till I fell asleep.

With ____ leaves ____ in the earth every year, the soil becomes richer and richer.

There was a _______look on his face when he met with the______problem. 

There are some health problems that , when _______ in time , can become bigger ones later on.

________the working efficiency，the boss allows the employees to have a coffee break.