I believe that it is the first one: "They are quickly replenished."
This question is incomplete; here is the complete question:
Which phrase is evidence of the limits of what science can study?
A. Only a phenomenon that a scientist can observe with instruments
B. Only a phenomenon that a scientist can observe without instruments
C. Only a phenomenon that a scientist will be able to explain with certainty
D. Any phenomenon that a scientist can observe or model
The correct answer is D. Any phenomenon that a scientist can observe or model
Explanation:
Science focuses on phenomena that can be objectively studied or witnessed. This includes any phenomenon a scientist can register using observation, instruments, or that can be represented through models. This is because, through observations or instruments, it is possible to prove the phenomenon occurs and understand how this happens; also, models can represent or recreate the phenomenon itself, which is essential to understand and explain the phenomenon. Moreover, science has an objective focus and due to this, aspects such as personal beliefs that cannot be represented through a model or be observed are not part of science. According to this, the correct answer is D.
Second one i think.......
Explanation:
probably because, X rays are used to ionise the gas molecules, which is loss of electrons, these electrons are absorbed by oil drops
