Answer:
Eighth week of pregnancy
Explanation:
At the end of the 8th week after fertilization (10 weeks of pregnancy), the embryo is considered a fetus.
It’s an addiction, most of the products if not all that involve nicotine are bad for your lungs
Answer:
Environment
Explanation:
In a research study, internal validity refers to how well an experiment was carried out and to what extent the piece of evidence supports a claim.
The lesser the chance of confounding in a study the higher the internal validity.
Study of memory is possible through learning the electrical activity created by neurons.
Therefore, thunderstorm will affect the readings hence it is an Environmental threat to the internal validity.