The alveoli are tiny air sacs in the lung. They have a relatively large surface area and thin walls. This structure allows –

Basically let's you breathe easier.

Explanation:

The alveoli are only one cell thick. Which allows relatively easy passage of oxygen and Carbon Dioxide between the alveoli and blood vessels. (Capillaries

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.