There is no need for you to look up every new word you ______ when reading. You have to learn how to guess the meanings of new word according to the context.
“Where did you find the professor who made the speech yesterday?” “It was in the hall ______ the students often have a meeting.”
It may have been at Christmas _____ John gave Mary a handbag.
_____ was very ______ that little Jim wrote the letter.
What is it _____ his daughter needs most?
Who was it _____ saved the drowning girl?