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The operating system that functions from typing commands is called a Command–Line–Based OS. Examples of this type of OS include UNIX and MS–DOS made by Microsoft. These features white or green text on a black screen and were primarily meant for professionals who had to learn lots of commands rather than everyday users.
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1.)
<span>((i <= n) && (a[i] == 0)) || (((i >= n) && (a[i-1] == 0))) </span>
<span>The expression will be true IF the first part is true, or if the first part is false and the second part is true. This is because || uses "short circuit" evaluation. If the first term is true, then the second term is *never even evaluated*. </span>
<span>For || the expression is true if *either* part is true, and for && the expression is true only if *both* parts are true. </span>
<span>a.) (i <= n) || (i >= n) </span>
<span>This means that either, or both, of these terms is true. This isn't sufficient to make the original term true. </span>
<span>b.) (a[i] == 0) && (a[i-1] == 0) </span>
<span>This means that both of these terms are true. We substitute. </span>
<span>((i <= n) && true) || (((i >= n) && true)) </span>
<span>Remember that && is true only if both parts are true. So if you have x && true, then the truth depends entirely on x. Thus x && true is the same as just x. The above predicate reduces to: </span>
<span>(i <= n) || (i >= n) </span>
<span>This is clearly always true. </span>
Answer:
In studies about new medicines, researchers usually give one group of patients the medicine that is designed to treat an illness. They give another group of patients a placebo, which is taken the same way as the medicine but does not actually contain the ingredients of any medicine. Different medicines are tested in different experiments, but the placebos usually contain the same non-medical ingredients. If both groups of patients are healed, then researchers cannot be sure whether the medicine caused improvement, but if the group given the medicine is healed while the group given the placebo remains ill, researchers can conclude that the medicine causes the illness to go away.
In medical experiments, which group receives placebos?
the experimental group
the control group
both the experimental and control groups
neither the experimental nor control group
Explanation: