1.   But it is not prepared to accept that the mathematical models developed to explain the phenomenon are sufficiently proven.

2.   -- which was developed to explain the very real and painful phenomenon of large-scale unemployment.

3.   And now, with the American population becoming more educated, new explanations have developed to explain where the attention of younger readers may be wandering.

4.   In fact, the disk-wind theory was first developed to explain these extra-galactic jets.

5.   This theory of learned helplessness was developed to explain why a victim feels she is unable to leave an abuser.