1)They have i________ the price by 50% in the past two years

1)They have i________ the price by 50% in the past two years.
2) His first music teacher was a major i______ in his life.
3)For further i______ on the diet ,please write to us at this address.
4) He i______ that she should come tonight .
5)Do your parents take an i________ in your friends