1．i____________ to put liquid, especially a drug，into someone’s body by using a special needle
2．r____________ to make something smaller or less in size，amount, or price
3．a____________ someone who is very interested in something and spends a lot of time doing it
4．c____________ illegal activities in general
5．c____________ the way in which two facts, ideas, events etc.are related to each other, and one is affected or caused by the other.
