Hints

For LM-C02-C-001, use the convention stated in the problem.

For LM-C02-C-002, first convert all words to lowercase.

For LM-C02-C-003, split on spaces in this controlled example.

For LM-C02-C-004, training fits parameters; validation chooses settings; test is the final check.

For LM-C02-C-005, ask whether held-out evidence influenced the system.