A microscope is a scientific instrument which makes very small objects look bigger so that more detail can be seen.
PHRASE
（通常由于被认为存在问题)被仔细研究
If you say that something is under the microscope, you mean that it is being studied very closely, usually because it is believed that something is wrong with it.
例句
The media put their every decision under the microscope.媒体仔细研究了他们的每一个决定。