【小编寄语】查字典英语网小编给大家整理了初中英语词汇学习：What were you doing when the UFO arrived ，希望能给大家带来帮助!
1. land v. go, come from a ship, aircraft, etc. 靠岸;登陆
示例
The bird landed gracefully on the water. 小鸟优雅地停在水面上。
用法点击
land 用作动词时，后面可接on，in，at等介词表示具体时间或地点。例如：The plane landed safely at Tianhe Airport at 2 pm. 飞机于下午2点安全降落在天河机场。land 还可用作名词，意思是“土地;陆地。例如：She is glad to be on land again. 她很高兴重登陆地。
词汇拓展
谚语：Being on sea, sail; being on land, settle. 随遇而安。
homeland n. 祖国;家乡 landlady n. 女房东;老板娘
landlord n. 房东;地主 landmark n. 地标;里程碑
landslide n. 山崩 landscape n. 风景;地形
2. while conj. During the time that; at the same time as 当……时候;和……同时
示例
He was so tired that he fell asleep while he was doing his homework. 他是如此地疲倦以致于在写作业时睡着了。
用法点击
while 用作连词时，意思是“当……的时候，表示两个动作相伴随而发生。例如：While she was typing, her brother was playing with a ball. 当她在打字时，她弟弟正在玩球。while 还可以用于对同类的两个动作进行对比，意思是“而。例如：You like sports while I like reading. 你喜欢运动而我喜欢读书。while 用作名词时，意思是“一会儿。例如：After a while, there came a strange noise. 过了一会儿，传来一种奇怪的声音。
3. around prep. & adv. about; not far away (in place or time) 大约;在……周围
示例
The earth moves around the sun. 地球围绕太阳转。
用法点击
around 既可以用作介词，也可以用作副词，意义上差别不大。如：He asked me to come here around the o'clock. 他要我10点左右来。(用作介词)She turned around at such a noise. 听到这样的吵闹声，她回头看了看。(用作副词)
辨析round 和around：
around 与round 通常可以互换，只不过美式英语常用around，而英式英语常用round，例如：You can see the post office round / around that corner. 在那个角落附近你就可以看到邮局。它们的不同之处是：round可以用作形容词、副词、介词、动词、名词;而around只能用作副词或介词。例如：He has a round face. 他有一张圆圆的脸。(用作形容词)The river rounded the stones. 河水使石头成了圆形。(用作动词)