Answer:
D..................................
Answer:
Explanation:
a bird feather is biotic because it was made on a living thing. fog is abiotic because its not living or was never living. i might be wrong about the feather tho.
Answer:
1440
Explanation:
Members except president, secretary and joint secretary = 9−3=6
Their arrangement = 6!
No. of arrangements of secretary and joint secretary at wto places
=2!=2
Total arrangement =2×6!
2 x 6! = 1440
Both have a pump that pushes materials throughout the organism.