Answer:
The only thing that can scratch Corundum is diamond.
Explanation:
We refer to the Mohs Hardness Scale for the hardness levels. We can see that Corundum is a level 9 which is the second highest so at a level 10 we see diamond, therefore diamond is the only thing that can scratch Corundum.
Answer:
C. Responsiveness and timing
Explanation:
I just know it, I really don't know how to explain
D. it serves as a link between membrane proteins on adjacent membranes.