In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

[Q]: Coral reefs make up only _ per cent of the area of the Great Barrier Reef.
[A]: five

[Q]: Autism is _ to four times more likely to affect boys than girls.
[A]: three

[Q]: Yeasts have _ spores because they are single celled.
[A]:
no