Answer:
placebo control group
Explanation:
In order to determine that a drug has any effect in the body participants of a study are divided into two groups a group which actually receives the treatment and the other group receives a fake treatment. The participants are unaware of which group they belong to.
The fake treatment group is called the placebo control group. If the drug is actually effective then the placebo control group should not shoe the same effects that the treatment group is showing.
Here, the capsule received by group 2 looks like the capsule with the Ginkgo Biloba herb. The participants of group 2 should not show an increased blood flow to the brain. The participants of group 1 should show an increased blood flow to the brain. This would prove that the Ginkgo Biloba increases blood flow to the brain.
Thunderstorms usually occur at cold fronts.
D. Taiga. It says the it contains the largest expanse of untouched boreal forest in the world.
Taiga is the world's largest land biome, making up 29% of the world's forest cover. The largest areas are located in Russia and Canada. The taiga is the terrestrial biome with the lowest annual average temperatures after the tundra and permanent ice caps.
The answer is A, Cotten was a major cash crop and relied on the work of slaves which was at the time more important than growing business
It became the largest nation in the world
