A crust of ice的用法和样例：
- It is very dangerous to walk on the thin crust of ice.
- She dipped a crust of bread in the cabbage soup she'd made.
- It is getting colder, too, and the spray has built a heavy crust of ice on the bow, weighting the skiff.
- The lorry went into a spin on a patch of ice.
- Every morning I make a pitcher of ice tea.