I think it's D. The use of farming to feed a larger population.
<span> the front-line trench (or firing-and-attack trench), the support trench, the reserve trench, and the communication trenches </span>
Answer:
it kinda means what are you up to/how you doing
The government impose September 11 security fees on passengers in order TO PAY FOR SECURITY AT AIRPORTS.
After the terrorist bombing attack that occurred in USA in September 11, 2001, the US government set up special security agencies that are responsible for handling security activities in US airports. September 11 security fee is part of the money that is used to fund these agencies.