真空激光准直长管道由若干根钢管焊接而成，每根钢管焊接前或一段管道焊好后，均应作平直度
题型：单项选择题
问题：
真空激光准直长管道由若干根钢管焊接而成，每根钢管焊接前或一段管道焊好后，均应作平直度检查，不平直度不得大于（）。
A、10mm；
B、20mm；
C、30mm；
D、50mm。
题型：单项选择题
短文改错（共有10小题；每小题0.5分，满分5分）
下面短文中有10处语言错误。请在有错误的地方增加、删除或修改某个单词。
增加：在缺词处加一个漏字符号（∧）， 并在其下面写上该加的词。
删除：把多余的词用斜线（\）划掉。
修改：在错的词下划一横线，并在该词下面写上修改后的词。
注意：1. 每处错误及其修改均仅限一词。
2．只允许修改10处，多者（从11处起）不记分。
例如：It was very nice to get invention to spend ∧ weekend with you. Luckily I was completely
Recently，our school has held the meaningful discussion on whether it is reasonable for middle school students to have classes on weekends．Some of our classmates believe we should have classes on weekends．because we can make fully use of the free time to review the lessons we had learnt．Some others are against the opinion，saying we had better to have a good rest on weekends so that we can work effective during the weekdays．The rest agree with neither of the opinion．They have the view which keeping the balance between work and play are both important for us．They suggest one day of the weekend should used to learn our lessons and during the other day they do something interested or have a rest．the am
free then, so I’ll to say “yes”. I’ll arrive in Bristol at around 8 pm in Friday evening.
on