What is mentruation? give example​

a cyclical discharging of blood

Explanation:

menstruation (a period) is when blood and tissue come out of your ovaries. Typically, menstruation can last about a week. Symptoms are: bleeding, discharging, cramping, weight gain, and soreness in chest. You can’t menstruate during pregnancy, or after menopause.

Explanation:

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.