【正确答案】正确答案：This rule reveals two points; first, it shows one possible allomorph of the morpheme {D} , and this allomorph has the phone(-id)as its element; second, it shows the according phonetic environment in which that allomorph can occur, that is, it will be pronounced as(-id)when it appears after the phone(t). In this rule, the arrow means the realization, and the bar indicates the environment of the target element.