Arnold K H Tan's answer to Hui Ling's Secondary 4 Biology question.
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
Note: 21% oxygen in air is the safer number to use, as its explicitly mentioned in the syllabus, although 20% is still accepted too. Download the latest syllabus from www.seab.gov.sg for all your subjects.
Date Posted:
6 years ago
360 Tutoring Program