Dr. Foster was studying the effects of zinc on the common cold. She hypothesized that zinc would shorten the duration of the common cold. She conducted a study in which patients suffering from a cold were given daily doses of either zinc or a placebo and the amount of time it took for them to feel better was measured. whats the independent variable: whats the dependent variable: whats the constant variable: whats the control group: whats the experimental group:

Explanation:

The independent variable is one that does not need to be influenced by anything to be measured. In addition, this variable influences the result of the experiment. In the above experiment, we can see that Dr. Foster is analyzing the influence of zinc doses on the duration of colds, with that we can conclude that the zinc doses (which influence a result) are the independent variables.

The dependent variable is one that needs an influence to be measured. This influence is the independent variable, which influences a result within the dependent variable. As we can see in the above experiment, the duration of the cold is influenced by the zinc dozen, therefore, the duration of the cold is the dependent variable.

The experimental group is the group that receives the element that is being tested in the experiment. The experiment is testing zinc doses, so the group of patients who received the zinc doses is the experimental group.

The control group is the group that did not receive the element that is being tested in the experiment. The group that did not receive the zinc doses is the control group.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]