Hey There!
Here is your answer:
Your answer is that a experiments should be controlled because the experiment could go out of control which could harm or hurt someone.
Also the definition of a controlled experiment is a part of the experiment that's not touched.
Ex: Water is your controlled experiment that's because our not doing anything to the water.
If you need anymore help just ask me!
Hope this helps!
<span>The amount of goods and services produced by an economy divided by the amount of resources used to make those goods and services, measures economic D. productivity.</span>
Cell division is when a cell under goes mitosis. Which divides in top to create another cell of the same kind.
In Gamete a haploid germ of either sex unites with the opposite sex to have sex and have a zygote.
The answer to this question would be: <span>lung cancer
In 1950, the medical practitioner doesn't know the relation of cigarette smoking with lung cancer. In that era smoking advertising is very massive and some physician even helps it. This cause increased amount of lung cancer incidence. The amount of lung cancer continues to increase till 1980-1990</span>
