The English Circle

  http://www.focus.olsztyn.pl/en-ordinal-and-cardinal-numbers-in-english.html#.Xp3GA2YzbIU

  1.  https://engblog.ru/infinitive-with-and-without-to 2. https://engblog.ru/test-infinitive-with-and-without-to 3. https://www.native-english.ru/tests/the-infinitive-with-or-without-to 4. https://onlinetestpad.com/ru/testview/738159-infinitiv-v-anglijskom-test-na-nalichie-ili-otsutstvie-chasticy-to  5.  https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-46192.php 6.  https://www.ego4u.com/en/cram-up/grammar/infinitive-gerund/exercises?02