I believe the answer is: double-blind experiment
In double blind experiments, the subjects that receive the treatment is remained unknown by both the researchers and the subjects until the experiment is finished. The main purpose of double-blind experiment it eliminate the bias of perception that might exist among researchers.
A peninsula is an area of land (like Florida) that hangs off of land like an island but one part's connected. A tundra is wide open, flat land, like the Alaskan Tundra. A mountain range is a long string of mountains side by side like the Appalachians. And for mountain barriers (I'm not sure I fully understand but) it seems like theirs more dew and wind for example on one side of the mountain and the others the opposite because the mountain blocks it (not completely sure bout the mountain part but i think its right!). Ocean currents is the force of the wind blowing up against the sea, helping to create the waves, and of course the pull of the moon! Hope I helped! Sorry I can't help with the wind barriers part!
Identical twins are two people born at the same time from the same person that look alike. The difference is they may develop is in personality from different experiences but usually they have different birthmarks
The answer is A, hope this helps
