1. A thousand years later, citizens on Earth can dispose of rubbish through ecological system. 2. The snake is so greedy that it swallows up that mouse.
In a thousand years' time, citizens on Earth may be able to dispose of waste through the ecological system. This snake is greedy enough to swallow up that mouse in a bite.
A thousand years later, citizens living on the Earth may possibly dispose rubbish in an ecological way. This snake is so greedy that it swallows up that mouse mouthfully.
1 The citizens on the earth maybe use ecological system to dispose of rubbish thousands of years later. 2 This snake is so greedy that it swallow up that mouse mouthfully.