<span>The correct answer is B. A plane contains at least three noncollinear points. What this means simply put is that the three legs touching the ground constitute a plane and is stable. If there were only 2 it could tip over easily. If there were 4 legs then one leg might not touch the ground and might hang in the air. This way, when there's three, all three will at all times touch the ground and will constitute a plane.</span>
<span>This is called the progressive verb form. Most commonly known are the present and the past progressive, known also as present and past continuous forms of a verb. And example would be saying that someone "is working", or "was working", where we use the participle working and helping verb "is", that is, "was".</span>
Der Hund
Der Schuh
Der Handy
Der Tennisball
Der Fotoapparat
