When might you see a colorful streak across the sky?

when there is a rainbow

Explanation:

After its rained, sometimes you can see a rainbow. Some are very vibrent, while others are quite faint.

Explanation:

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

by 1880, germany had more rail lines than great britain and russia.