Have the students try to fill the gaps and then discuss the words they've chosen. If they've made a mistake, explain why it is not correct. Remind them to read the whole sentence before and after the gap to look for clues about what type of word fits.
1) In some cases, more than one word is possible for a gap, but you must only write one.
2) Consider whether a pronoun, determiner, auxiliary verb, question word or preposition can fit into the space.
3) In some cases, students will need to recognise phrasal verbs or common fixed phrases.
4) Do not use the first word that comes to mind. Remember to consider multiple options before choosing an answer.
5) Once all the gaps are completed, re-read the text to see if it makes sense.