Perform spelling and grammatical corrections to the given sentence.
Teachers around the worldr have been expressin concern over falling literacy rates.
Teachers around the world have been expressing concern over falling literacy rates.
Complete the following task based on the instruction and optional input provided.### Instruction:
Perform spelling and grammatical corrections to the given sentence.

### Input:
Teachers around the worldr have been expressin concern over falling literacy rates.

### Output:
Teachers around the world have been expressing concern over falling literacy rates.