用CO2焊进行对接焊时,焊缝两端加引弧板和息弧板是为了起到()作用。
A.没有任何作用,不用加
B.减少焊接应力,避免未焊透及其它焊接缺陷的产生
C.为了增加焊缝美观
参考答案:B
假定英语课上老师要求同桌之间交换修改作文,请你修改你同桌写的以下作文。文中共有10处语言错误,每句中最多有两处。错误涉及一个单词的添加、删除或修改。
增加:在缺词处加一个漏词符号(∧),并在其下面写出该加的词。
删除:把多余的词用斜线(\)划掉。
修改:在错的词下划一横线,并在该词下面写出修改后的词。
注意:1. 每处错误及修改均仅限一词;
2. 只允许修改10处,多者(从第11处起)不计分。One day a child was playing with a vase in great value. He careless put his hand into it. Hard as he tried, he could not pull it out. His father tried his best, too, but their efforts were in a vain. They were thinking of breaking the vase whenever the father said, “Now, my son, why have one more try? Open your hand or hold your fingers out straight as you saw I doing, and then pull.” To his surprise, the child says, “I can’t hold my fingers straight like that, because I don’t want to drop my penny.” Thousand of us sometimes are so busy hold on to the world’s worthless penny that we cannot achieve liberation.
断肢在行再植手术之前应保存在
A.乳酸林格液
B.75%酒精
C.10%福尔马林溶液
D.用无菌或清洁敷料包扎后干燥冷藏
E.置于37℃恒温箱中