9. how are bacteria different from viruses?
(a) bacteria can cause diseases.
(b) bacteria possess cell structures such as cell walls, flagella and ribosomes.
(c) bacteria are very small in comparison to a virus.
(d) bacteria are only active when inside living cells.

Bacteria are one-celled organisms that can be found naturally throughout our bodies and in our environment. ... Viruses are smaller than bacteria and they attach themselves to another living cell and use that cells' genetic material to reproduce themselves. Most viruses cause disease.

answer; i believe the answer is hydraulic action;

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.