Answer:
pulse
Explanation:
it's a pulse your feeling
Through the placenta during pregnancy
Breathing of contaminated air is the most common way, some can pass through the skin into the blood stream e,g acid
Answer:
experimental method.
Explanation:
Based on the information provided within the question it can be said that the method that is being described is called the experimental method. This method, like described in the question, refers to manipulating one variable in order to see the effects that it causes in another variable, and is done in order to test the hypothesis and decide whether it s refuted or not.
The answer is vaccination! hope this helped ;)
