April
From the transcript (Appendix, Unit 8, printed page 275): “Interested students from Grades 9 to 12 may collect the registration form from the school office starting Monday, 04 April. The last date to submit completed forms is Friday, 08 April.”
How to arrive at it while listening. The announcement never says the words “the courses will begin in April”. It gives you two dates, and both fall in the same month — registration opens on 4 April and closes on 8 April — so the courses start in April. April is also the only month named anywhere in the announcement, which is your confirmation. In a gap-fill of this kind, the answer is sometimes the one word every relevant sentence has in common, not a phrase lifted whole.
Listening tip: dates and numbers are the easiest details to lose and the easiest to note. Before the recording starts, read the six blanks and put a small symbol beside each — a calendar for a date, a list for course names, a person for ‘who’. You will then be waiting for the right kind of word instead of trying to catch everything.