I ran into this question from Cambridge IELTS 10 while doing a practice test with students.
A lot of them missed points because they put singular instead of plural, or vice versa.
Write NO MORE THAN TWO WORDS for each answer.
Premier members can bring some 19 _____________ every month.
Based on the grammar in this sentence, should the answer be singular or plural (assuming the noun is countable)?
Which word in the question tells us this?
It can be difficult to think about this while doing the question, but you should use your review time or the 10 minute answer transfer time to double check your singulars and plurals.