Research studies in which half the participants are told they are drinking alcohol and half are not, with half of each group actually receiving alcohol and half not, are using the design.

The method used would be a clinical study design.

Explanation:

The clinical study design - This can be defined as research studies which involve the formulation of trials and experiments. The clinical study design can be seen as observational studies in medical, clinical and other types of research involving human beings

balanced placebo design.

Explanation:

So, let us fill in the gap in the question above. Note that the capitalized words are the missing words to be filled in the gap.

"Research studies in which half the participants are told they are drinking alcohol and half are not, with half of each group actually receiving alcohol and half not, are using the BALANCED PLACEBO design''.

The placebo design is used in the research studies to for the study or evaluation of the effect of of various types of beverages and alcohol. One of the limitations of balanced placebo design is that it can not be used to determine or measure the effect of little amount or quantity of the alcohol or beverages.

to keep it profesional sex is the main way humans reproduce

explanation:

a progressive heart disease that affects pumping action of the heart muscles.