Random events mean that the probability of their occurrence is a constant. For example, in dice, the probability that the number of points is 1 is 1/6. Will not change because of the size of the dice (as long as the dice are uniform).
The uncertain event contains different possibilities, such as throwing a beer bottle cap, so the size of it cannot be accurately determined.
One is to divide courses into basic courses, expanding courses and research courses, which is ()
Courses are divided into basic courses, expanding courses and resear