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.

Comprehension:
Essaouira's origins stretch back to prehistoric times, and this spot on Morocco's Atlantic coast (1)______ a centre of culture and commerce ever since. (2)______ centuries, the harbour town was an important trading post (3)______ both a seaport and as the north-western terminus of a caravan (4)______ stretching across the desert to Timbuktu (5)______ Africa’s interior.