Look at the "How to do it"box
Look carefully at what part of speech is missing
REMEMBER: The words are usually short, for example prepositions (on, in, at), linking words (because, also), auxiliary verbs(helping verbs: be, do, have), pronouns,(he, she, they), relative pronouns (which, that, whose, whoever, who,) etc.
TIP: Check your answers using the information in the Tip Box