Answer:
Step-by-step explanation:
For airplane material, weight is important. So the answer is:
O They weigh much less than other materials of the same strength.
Moderator: This is a valid question and in the right subject of AP. It is not a test question as it has been up for 6 days before I answer. Please review before deleting this question - I do not understand why it has been flagged. Thank you.