The appropriate answer is A. the density of ice would be greater than the density of liquid water and so ice would not float. Density can be defined as mass per unit volume. Any substance whose mass is great and occupies a relatively small volume is going to be dense.
Water expands by nine to ten percent when it freezes and this expansion increases the space occupied or the volume and so the density of ice is less than water.
The type of glial cells are particularly at risk from the disease are the Schwann cells. This disease is caused by a bacterium, Corynebacterium diphtheriae, and is caused when the bacteria releases a toxin, or poison, into a person's body. The Schwann cells produces insulating myelin sheath that covers the axons of many neurons. These cells may suffers immune or toxic attacks with diphtheria infection.
I may be wrong but I think it’s the second one. They speed up reactions, and there’s a certain enzyme for a certain reaction.