lift raisebland tickled ridiculeddeliver least stop pause overdoexaggerate offends receiver hogA joke can cause great amusement and 1)________the mood of the gathering. A speaker who puts some relevant and well-told jokes into his or her speech will be appreciated by the audience who are often bored with 2)________presentations and are crying out for a little entertainment.Here are some tips on how to tell a good joke:1. Select. Choose three or four jokes that really 3)________you from the internet or a joke book. If you are giving a talk or presentation, look for ones that have some relevance so that you can work them into talk. Have one or two generic or topical ones that you can use on any occasion.2. Practise. Practise them aloud in front of a mirror if possible. 4)________them with style, confidence and panache. Focus on the punch line and ensure that you can deliver it perfect.3. Choose your moment. If there is a convenient hook in the conversation for one of your jokes you can introduce it then. Otherwise wait for a pause. Sometimes the most amusing jokes occur when people 5)________expect the teller to tell a joke. So, if appropriate, be serious as you introduce the story and then catch your audience out with the punch line.4. Deliver slowly and with confidence. Many people ruin jokes by rushing them. Slow down a little. Try to 6)________for effect before you deliver the punch line. That can add enormously to the impact.5. Match the joke to the audience. Jokes often challenge taboos so it is OK to risk a tiny amount of offence to one or two people. But if your jokes seriously 7)________people then you were guilty of misjudgment. Choose wisely.6. Reciprocate. Never finish anyone else’s joke. Always laugh or smile even if you have heard it before. Be a good joke teller and 8)________.7. Develop. As you build experience and confidence, try more and different jokes. But don't 9)________it. Don't hogthe conversation with one joke after another. A few really good jokes that you can tell with perfect confidence is the aim.Finally, have some one-liners to throw in from time to time. Here are a couple to get you going:* Velcro—what a rip-off!* 'Shut up!' my father explained.Funny jokes make the world a more interesting place. Enjoy your joke telling!

气体保护焊的焊接热影响区一般都比手工电弧焊的小，原因是（）。

A.保护气体保护严密
B.焊接电流小
C.保护气体对电弧有压缩作用
D.焊接电弧热量少

氩弧焊的焊接质量比较高，但由于焊接成本高，所以（）一般不用氩弧焊焊接。

A. 铝合金一般结构
B. 不锈钢结构
C. 低碳钢
D. 耐热钢结构

埋弧焊比焊条电弧焊的生产率高，主要原因是（）。

A.实现了焊接过程的自动化
B.节省了更换焊条的时间
C.可以采用大电流密度焊接
D.A 、B和C

下列的焊接方法中，不属于压焊的是（）。

A. 摩擦焊
B. 激光焊
C. 点焊
D. 缝焊

钎焊按（）分为软钎焊和硬钎焊两大类。

A.接头强度
B.接头硬度
C.钎料熔点
D.钎料硬度

焊接时一般要对被焊区进行保护，以防止空气的有害影响。如焊接低碳钢时，焊条电弧焊采取的保护措施分别为（）。

A. 熔渣
B. 气体保护
C. 气体保护、熔渣
D. 都不是

下列的焊接方法中，不属于熔焊的是（）。

A.电渣焊
B.缝焊
C.氩弧焊
D.埋弧焊

对于氩弧焊，下列说法不正确的是（）

A. 氩气成本较高
B. 气体保护效果好
C. 宜在室内作业
D. 不适合手工操作

下列焊接方法中属于熔焊的是（）

A.焊条电弧焊
B.电阻焊
C.软钎焊
D.点焊