Explanation:

The correct statements related to Special Economic Zones (SEZs) are:

1. It is a duty-free enclave to be treated as foreign territory for the purpose of trade operations and duties and tariffs.

   • Correct. SEZs are considered as foreign territories for trade operations, and they offer various exemptions and benefits, including duty-free import and export.

2. The corporations in SEZs will not have to pay any income tax on their profits for the first five years and only 50% of the tax for 5 more years thereafter.

   • Correct. SEZs provide income tax exemptions to the units operating within them. For the first five years, there is a complete income tax holiday, and for the next five years, a 50% concession is provided.

3. A SEZ does not require a license for exports.

   • Correct. SEZs enjoy certain exemptions and relaxations, and one of them is that units within SEZs do not require a license for exports.

So, all the given statements (1, 2, and 3) are true.