Question

drag the missing word into place
following kristallnacht, jewish people in nazi - occupied territories were rounded
up and forced into : dirty, crowded, walled - off areas that
functioned as open - air prisons.
ghettos
concentration
camps
systematics

Explanation:

After Kristallnacht, Jewish people in Nazi - occupied territories were forced into ghettos. Ghettos were dirty, crowded, walled - off areas that functioned as open - air prisons. Concentration camps were more about mass imprisonment and extermination with a more formal and large - scale infrastructure for atrocities. Systematics is a field of study (related to classification in biology etc.) and not relevant here.

Answer:

ghettos