How do I keep a conversation going

Inspired by the example of that great cornellian, vladimir nabokov, some of your friends have become amateur lepidopterists (they study butterflies). often when they return from a trip with specimens of butterflies, it is very difficult for them to tell how many distinct species they've caught— to the fact that many species look very similar to one another. solution

Completar fill in the blanks with words from the list based on the panorama cultural video.

How would having more railroad tracks be advantageous during a war