Vivian, an african american, finds that she seems to explain how she and janet, a european american, became friends much more frequently than she has to explain her friendships with other african americans. sometimes she and janet laugh about the curiosity of others. vivian and janet have encountered a challenge to intercultural relationships.

Vivian and Janet have encountered  the need for explanation, a challenge to intercultural relationships.

Explanation:

Vivian, as an African American, has to explain how she became friends with Janet, an European American, because people assume that cultural differences between African Americans and European Americans are too big to be overcome.

i don't know the answer to this

answer; no longer than a reasonable period of time;