Write a paragraph summarizing the article The Layer of Earth

 Scientists understand much about Earth's structural layers — the inner core, A cut-away of Earth's layers reveals how thin the crust is when compared to The mineral crystals that make up rock are usually too small to be seen with the unaided eye.  

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

have a great day because if you dont you and i will be sad