Prior knowledge can be gained from personal experience and

A)
forming welldeveloped hypotheses
listening to opinions of other people on a topic,
researching previous experiments and results on a topic.
no other methods. It can only be gained by personal experience.

well schools are being forced to embrace computers. unlike their "digital immigrant" teachers, these students are "digital natives", born into a world where technology is an integral part of everyday life. almost every student has access to a multitude of computers, laptops and tablet devices. it would be crazy to assume an assignment would  not be written on computer in this day and age.

don't delete this trying to

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.

answer; convade;