In the following three passages, some of the words have been left out. First read the passage over and try to understand what it is about. Then fill in the blanks with the help of the alternatives given.

One of the major causes of the failure of (66) countries on the economic front is their (67) to evolve a judicious mixture of (68) substitution and export promotion. Today, Bambia, which (69) on imports after its independence 20 years, (70).

• since

• ago

• earlier

• earlier