High Note 3 unit 4

https://test-english.com/grammar-points/b1/have-to-must-should/

https://www.perfect-english-grammar.com/modal-verbs-of-obligation-exercise-1.html

https://test-english.com/grammar-points/b1/can-could-be-able-to/

https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-80352.php

https://www.perfect-english-grammar.com/modal-verbs-of-ability-exercise-1.html

modal verbs

https://test-english.com/grammar-points/b2/relative-clauses/

https://www.perfect-english-grammar.com/relative-clauses-exercise-1.html

https://www.perfect-english-grammar.com/relative-clauses-exercise-2.html

https://www.perfect-english-grammar.com/relative-clauses-exercise-3.html

https://www.perfect-english-grammar.com/relative-clauses-exercise-4.html

relative clauses

LEARN SOME USEFUL AIRPORT ENGLISH FOR YOUR FUTURE TRAVELS

https://www.oxfordonlineenglish.com/airport-english

VOCABULARY PRACTICE - TRANSPORT

https://learnenglish.britishcouncil.org/vocabulary/intermediate-to-upper-intermediate/air-travel

https://test-english.com/vocabulary/b1-b2/air-travel-b1-b2-english-vocabulary/

HIGH NOTE 3

unit 4