In the following passage some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each blank.
During organised tours, tourists can visit a former Nazi compound 40 kilometres (1)______ Berlin called the ‘Forbidden City’. Twentythousand people (2)______ here every year to learn about Nazi military history. The Nazis (3)______ militarily active at the compound,(4)______ was kept secret in a forest and behind a fence. The Nazis (5)______ much of World War II from here.
Select the most appropriate option for blank number 4.