Answer:
the answer would be c
Explanation:
because if they measure two types of waves the answer would then be c
Answer:
1- It's often impossible to repeat trials on the same subjects. 2-Subjects may report an inaccurate medical history. 3-It can be difficult to control all possible variables. 4-It's impossible to come up with testable scientific questions for human subjects.
Explanation:
i hope this helps u
Answer:
nucleus,the central vital organ of an animal or person