B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
Answer:
The lynx's principal food source is the snowshoe hare. These two species' population cycles are intertwined. When hares are abundant, lynx consume almost nothing else and kill two hares every three days. When hares are sparse, lynx eat mice, voles, squirrels, grouse, ptarmigan, and carrion.
In aquatic plants, water passes among the tissues and provides the medium for gas exchange. In terrestrial plants, air enters the tissues, and the gases diffuse into the moisture bathing the internal cells.
Hope this helps
<span>An element is a substance that cannot be broken into other substances further.An element is composed of one type of atoms all over. Like a molecule can be divided into atoms further. For example, Water is a molecule which is made up of Oxygen (O), Hydrogen (H). Here, Oxygen and Hydrogen are elements and cannot be further broken down into other substances.</span><span />
