Read the passage carefully. To the south and southeast of China are the Himalaya Mountains. These are the highest mountains in the world. They provided a nearly impassable border for Ancient China, keeping the area isolated from many other civilizations. They were also important to Chinese religion and were considered sacred.

– “Ancient China: Geography,”

Ken Nelson

Using context clues, which phrase best defines the word impassable?

separate or apart
tall and forbidding
unable to be crossed
of divine or holy origin

Unable to be crossed.

Because, im-possible, im-passable. the prefix “im” usually means cannot.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

we need the chart or check box