n.外殼；堅硬的外殼；面包皮

vt.蓋以硬皮

vi.結(jié)硬皮

The earth's crust is layered.. 地球的外殼是分層的。

The crust on the snow was thick enough for us to walk on it. 外層的雪已經(jīng)凍硬，可以在上面行走。

Please cut the bread into slices and remove the crust. 請將面包切片并去除外殼。

The crust of the bread is burnt. 這塊面包的外皮烤焦了。

The snow crusted the lake last night. 昨夜的雪使湖面結(jié)了冰。

The snow may crust at night, due to outward radiation. 由于外部輻射，晚上雪可能結(jié)成雪殼。