Statements:

1. Only one of statements 2 and 3 is true.
2. Statement 3 is false.
3. Statement 4 is true.
4. Statement 1 is false.

Possible solutions:

1. If statement 2 is true, then statement 3 must be false, which contradicts statement 2. Therefore, statement 2 is false.
2. Since statement 2 is false, only one of statements 2 and 3 can be true. Therefore, statement 3 must be true.
3. Statement 4 is true according to the given information.
4. If statement 1 is true, then only one of statements 2 and 3 can be true, which contradicts statement 1. Therefore, statement 1 is false.

Based on the above deductions, the true statements are:

1. Statement 3 is true.
2. Statement 4 is true.