expense  n. 費用，開銷，花費
[特征]
- what are the expenses of these goods?
這些商品的費用是多少？
- a new car can be a great expense.
買一輛新汽車要花很多錢。
[備考必背] 重要詞組
at one's expense  由某人付款
- we were all entertained at tom's expense.
我們全由湯姆請客。
at the expense of 以……為代價
he became a brilliant scholar, but only at the expense of his health.
他成為了一位卓越的學者，卻犧牲了健康。
at any expense 不管花費多少錢
- he wanted to buy the book at any expense.
不管花多少錢他都想買這本書。

explain  v. 解釋，說明
[特征]
- the boy was explaining to the teacher why he was late.
這個男孩正向老師解釋他為什么遲到。
- please explain to me where to begin and how to do it.
請向我說明從哪里開始以及怎樣做。
[考點]
①explain后面不能接the reason，這一點經(jīng)�？嫉健�
（誤）can you explain the reason why you were late?
（正）can you explain why you were late?
你能解釋一下為什么遲到嗎？
②表示“給某人解釋……”，explain后不直接接某人，也不用for，而用介詞to。
（誤）the teacher explained us this problem.
（正）the teacher explained this problem to us.
老師給我們解釋了這道難題。
[備考必背] 派生詞
explanation  n. 解釋，說明
- the text still needs explanation.
課文還需要被解釋。

explode  v. （使）爆炸，（突然）爆發(fā)
[特征]
- it's a custom to explode fireworks to celebrate the spring festival.
燃放爆竹慶祝春節(jié)是一種習俗。
- the bomb exploded near the tall building.
炸彈在這座高樓附近爆炸了。
[備考必背] 重要詞組
explode with anger 勃然大怒    explode with laughter 哄堂大笑
- the audience exploded with laughter.
觀眾哄堂大笑。

expose  v. 使暴露，使曝光，揭露
[特征]
- don't expose your skin to the flaming sun.
別把你的皮膚暴露在炎熱的陽光下。
- this film has been exposed.
這片子已經(jīng)曝光了。
[備考必背] 重要詞組
expose ... to ... 把……暴露在……
- the company exposed the plan to the newspapers.
公司向幾家報紙透露了這個計劃。