Mark each statement if it describes a change in historical knowledge based on new discoveries. a. historians know more about ancient sumer today than historians did long ago because of archaeological digs over the last two centuries. b. when king tut’s tomb was discovered undisturbed in the 1920s, we gained a greater understanding of the egyptians’ belief in the afterlife. c. with the discovery of pompeii, we learned that life for the upper-class romans offered comforts and pleasures. d. new information about the trojan wars came to light when the iliad was deciphered for the first time in the late 1930s.

The key emphasis here is on the "recent discoveries".

Let's go through the options:

A. Historians know more about ancient Sumer today than historians did long ago because of archaeological digs over the last two centuries.
- yes, I think that this is correct: archaeological excavations are fairly recent.

B. When King Tut’s tomb was discovered undisturbed in the 1920s, we gained a greater understanding of the Egyptians’ belief in the afterlife.
-this is absolutely correct! his tomb was discovered in 1922.

C. With the discovery of Pompeii, we learned that life for the upper-class Romans offered comforts and pleasures.
- I would say that this is correct, althougth it is not a "recent" discovery - it has been already discovered as early as 1600.

D. New information about the Trojan Wars came to light when the Iliad was deciphered for the first time in the late 1930s.
-this is false: the Illiad was never truly lost and it didn't need to be deciphered.

Primary sources are usually  more accurate and are written by someone who experienced it or witnessed it. secondary sources are those who heard of it after the fact that can lose details and or twist the event in a light that benefits them.