Answer:
Weight of the soil (500g)
Explanation:
According to this question, some students are conducting an experiment in order to find out which of the different soils used absorb heat the fastest. For the first test, they put 500 grams of SAND in a beaker and put a thermometer in the sand.
In an experiment, the variables that must be kept constant for all the groups is called the CONSTANT OR CONTROLLED VARIABLE. This is done in order not to influence the outcome of the experiment. In this case, the weight (500g) of the soil should be kept the same for all other tests.
This means that for the remaining soil being tested, 500g of each type of soil should be used.
Answer:
B. It is done by humans to select certain traits useful to us.
Explanation:
There are two main types of selection: natural and artificial. Natural selection is all of the other answers, it is seen over generations and allows the fittest to survive. It also occurs with no human intervention. However, artificial selection is done by humans. It occurs when humans breed animals to best fit their needs. This is best seen in dog breeding.
A. divided by the number of days in the billing cycle.
