Answer:The technique use in this study is referred to as a double blind
Explanation:
A double blind study is the one that both participants and experimenters or researchers are not made aware who is given a certain treatment.
In double blind researchers will not know if what they are receiving is part of the test itself as they interact with participants or they are receiving a placebo.
This process is useful to eliminate and avoid bias results.
For example, in the above text the effect of caffein on attention is being tested so the researchers will not know whether the drink given to them is actual for the test or just the placebo , they don't know who is in control of the experiment.
Answer:He unified small English kingdoms against the Danes.
Explanation:
I think it is D. the middle kingdom.
