I knew little about English when I first came to America. so I went to a language school everyday to learn English. One day, during the break I asked one of my classmates a question that I didn't understand. When I thanked her for it, she said: "You are welcome. It's a piece of cake." I thought to myself: America is really a society for money in which everything is done for pay. Thus I said to her: " I haven't taken any piece of cake with me today. what about " a piece of biscuit?"

She looked at me with a puzzled expression, then smiled. Knowing she hadn't got her words across, (get sth. across 为人理解，表达清楚）she said: " What I mean is, "no problem", and that it is only a trifling matter." Then I came to learn that " a piece of cake " is not only a pieced of cake but also means a thing that is very easy.

I am a nurse. I was lucky to work at an old people's home when I first came to America. As my English was poor, my aim at that time was to do more but speak less. One day  I gave an old lady, Linda, her medicine. Linda was over 90 years old suffering from aged dementia (痴呆症）. I tried several times, but Linda refused to open her mouth. Feeling anxious, I said without thinking: 

"Linda, open your big mouth, please. " Unexpectedly, Mrs. Linda got angry and shouted: " You have a big mouth. Leave me alone!" I was dumbstruck （惊呆的）and did not know where my mistake laid.

Later on a few pointers（指点，指示） from others made it clear to me that "big mouth" in American slang refers to a person who talks too much or spreads secrets around. No wonder Mrs. Linda got angry when she heard what I said. Actually I should have said: " Open your mouth wide."

45.1940　Jeep（吉普）Utility vehicle. Some say from G.P.general purpose. Probably influenced by Eugene the Jeep in Elzie C. Seger's comic strip Popeye.　多用途车辆。有人说这个词来自"多用途"（General Purpose）的首字母G.P.，但这个词的产生很可能受到（美国连环漫画家）埃尔齐.西格的作品《波佩》中的人名Eugene the Jeep的影响。

46.1941　Radar（雷达）A method of detecting the position and velocity of an object. Acronym of Ra(dio) D(etecting) a(and) R(anging).用来探测物体的位置和速度的一种方法，无线电探测定位的简称。

47.1942　Robotics （机器人学）The science of robots. A science fiction word come to life. Asimov's "There Universal Laws of Robotics"are accepted the rubric of SF.　这个词是从科学小说中流传开的。（美国科学小说家）阿西莫夫制定的"机器人学的3条普遍法则"被视为科学小说的程式。

48.1943　Dam Busters（大坝毁灭者）Nickname for the 617 Squadron of the RAF, which destroyed the dams with bombs that skimmed like ducks and drakes, and flooded the Ruhr. Bouncing bombs invented by Barnes Wallis.英国皇家空军第617中队的绰号。这个飞行中队在二战期间炸毁了德国的水坝，河水淹没了鲁尔区。他们使用的炸弹是巴恩斯.沃利斯发明的弹跳炸弹，飞机在贴近水面的高度投弹，炸弹便像在水面上跳动的鸭子一样直奔水坝。 

（待续）