accretional ice sheet的用法和样例：
- There are about 98% thick continental ice sheet and 2% barren rock.
- Their seaward edges are speeding up, and the ice sheet behind them is thinning.
- Like the Greenland ice sheet, the West Antarctic ice sheet is also losing mass.
- Their prediction is that a 3℃ rise in temperature In Greenland will trigger the irreversible melting of its ice sheet.