Lesson 17
第17课
deafen
v.使聋
A sudden explosion deafened us for a moment.
突然的爆炸声使我们耳聋了一会儿。
compel
v.强迫
He was compelled by illness to give up his studies.
他因病被迫放弃学业。
amuse
v.使笑
The storyteller's jokes amused the children.
说书人的笑话逗乐了孩子。
waterfall
n.瀑布
The Niagara Falls is one of the most beautiful waterfalls in the world.
尼亚加拉瀑布是世界上最美丽的瀑布之一。
straw
n.稻草
The farmers covered the barn floor with straw .
农民们把稻草覆盖在谷仓的地板上。
rare
adj.稀有的，半熟的
These flowers are very rare in this country.
这些花在这个国家很少见。
preserve
v.保存
The park was created to preserve some of the forests upstate.
这个公园是为了保护该州最北部地区的一些森林而建的。
motive
n.动机
There seemed to be no motive for the murder.
这起谋杀案看不出有什么动机。
oral
adj.口头的
He passed his German oral exam.
他通过了德语考试。
frost
n.霜
The car window was covered with frost.
车窗玻璃结了霜。
pre
放在词根前表示“先于，在...之前”
preheat
预热（pre+heat预热）
precaution
预防（pre+caution预防）
pre-war
战前（pre+war战前）