Exercise 4: Fill in the blanks with the correct forms of words in brackets. 24. We need __________ (buy) some more flour, a carton of eggs and two litters of milk. 25. They should _______ (make) a poster for their charity event. 26. Every summer vacation, Jenny _________ (take) part in some volunteer activities. 27. Last month, our group _______ (volunteer) at a soup kitchen. 28. Last summer, our school _______ (organize) a fun run to raise money for charity.