The idea that having a good cry do you (83) _____ is a very old one and now it has scientific validity since recent research into tears has shown that they (84) _____ a natural painkiller cal
The idea that having a good cry do you (83) _____ is a very old one and now it has scientific validity since recent research into tears has shown that they (84) _____ a natural painkiller called enkaphalin.
A. contain
B. retain
C. hold
D. keep