【最新直播課】
（新一）
【往期回顧】
今天我們接著來看第91課的“每課一句”。
一、課文原文
Lesson 91 Three men in a basket
A pilot noticed a balloon which seemed to be making for a Royal Air Force Station nearby. He informed the station at once, but no one there was able to explain the mystery. The officer in the control tower was very angry when he heard the news, because balloons can be a great danger to aircraft. He said that someone might be spying on the station and the pilot was ordered to keep track of the strange object. The pilot managed to circle the balloon for some time. He could make out three men in a basket under it and one of them was holding a pair of binoculars. When the balloon was over the station, the pilot saw one of the men taking photographs. Soon afterwards, the balloon began to descend and it landed near an airfield. The police were called in, but they could not arrest anyone, for the basket contained two Members of Parliament and the Commanding Officer of the station! As the Commanding Officer explained later, one half of the station did not know what the other half was doing!
——選自《新概念英語》第二冊，外語教學與研究出版社，1997年10月第1版
二、每課一句
The officer in the control tower was very angry when he heard the news, because balloons can be a great danger to aircraft.
注意本句話的結構：
1、第一層關係是由because引導的原因狀語從句，用來解釋控制塔上的軍官之所以生氣的原因；
2、第二層關係是在前面的主語中出現的由when引導的時間狀語從句，用來說明控制塔上的軍官是什麼時候發怒的。
本句話更加需要大家注意的是because引導的從句謂語動詞采用了can be的形式，即一般現在時的形式，而其主句的謂語動詞卻採用的是was very angry，即一般過去時的形式。
之所以這樣，是因為because從句所給出的原因是一個客觀事實，即無論何時對於飛機來說，氣球都是一個很大的威脅。既然是客觀事實，就需要用一般現在時來描述。
此外，要注意danger在這句話中的用法，即：
sth be a danger to sth.
...對...來說是個威脅
如：
A careless driver is a danger to us all.
粗心的司機對我們大家都是一種危險。
三、更多拓展
He informed the station at once, but no one there was able to explain the mystery.
注意這句話中的there意指“基地”，用作後置定語，修飾no one。
此外，要注意本句話中的was able to表示“具有...能力；得以...”，在此不用could，是為了凸顯氣球的出現是個較大的謎團，大家都無法解釋是怎麼回事。
如果覺得好，歡迎繼續關注廖懷寶的頭條號“新概念英語的教與學”！
閱讀更多 新概念英語的教與學 的文章
