well differentiated means it looks like the tissue that it came from. Poorly differentiated means it is hard to tell due to it not being differentiated into a particular cell line.
insulators...
A poorly-differentiated tumor resembles many different tissues. In contract, it's easy to name the tissue type of a well-differentiated tumor.
Fairly poorly. Although a simulator can create a smaller, non-violent vortex that resembles a tornado it cannot mimic the larger-scale dynamics that actually drive a real tornado.
foul ball
They die. This is called Natural Selection.
Films that do poorly at the box office are called 'bombs'. Example: Ishtar bombed at the box office.
most poorly
The adverb in the sentence is "seldom," as it describes the frequency with which he did poorly on tests.
I think the answer to this poorly phrased question is "a perfect square".
My apologies for any poorly structured answers. I was ill, so I performed poorly on the test.
A material that conducts electric current poorly is an insulator. Insulators have high resistance to the flow of electricity due to their tightly bound electrons, which do not move easily. Examples of insulators include rubber, plastic, and glass.
The French word for poorly is malade.