问题
单项选择题
PCB在焊接后，会在个别焊点周围出现浅绿色的小泡，不仅影响外观质量，严重时还会影响性能，是焊接工艺中经常出现的问题之一，其主要原因是（）。
A、在于阻焊膜与阳基材之间存在气体/水蒸气
B、焊接时风枪没有均匀加热
C、PCB来料不良，属于材料的问题
D、焊接的温度过高
答案
参考答案：A
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PCB在焊接后，会在个别焊点周围出现浅绿色的小泡，不仅影响外观质量，严重时还会影响性能，是焊接工艺中经常出现的问题之一，其主要原因是（）。
A、在于阻焊膜与阳基材之间存在气体/水蒸气
B、焊接时风枪没有均匀加热
C、PCB来料不良，属于材料的问题
D、焊接的温度过高
参考答案：A
I first met Sean one summer day. He carried a bag 36 with four clubs(球杆) and some balls. He was a lot 37 than other kids of his age. I heard he was 38 from cancer. Still , he always seemed to be smiling whenever I would see him with his friends, trying to 39 as far as he did. A year or so passed and I hadn’t 40 Sean .I had heard that his cancer was 41 him. Still, his friends said he was going to come here before long. 42 enough , he was there the following week. I 43 that one of his friends was carrying Sean’s bag. I saw Sean was having a(n) 44 time trying to drive the ball. Sean hit his last ball as hard as his fragile body would 45 .It flew up to the green and was out of sight. One of his friends 46 Sean walk up to the green. It was a(n) 47 walk because the green was higher than the tee(发球区). Suddenly I saw one boy pick up Sean’s ball and 48 it in the hole. Then he ran and 49 to look for his own ball. When Sean finally got to the green, he looked 50 because he thought he hit it over . Then he glanced in the hole. A smile 51 his face! The boys looked at each other and said , “You can’t tell me it’s a hole-in-one!” “No, really ! Look !” he said . They all acted 52 and as I watched , I thought Sean looked like the 53 guy I had ever seen. I never saw Sean or his friends after that day. 54 it was then that I learned just what golf should be . It’s not about what 55 you get or how far you drive. It is about caring for the friends you play with and enjoying the time you have with them.
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其中，在陶然亭的城北火车站东门侧有一家烟草持证零售户，其零售许可证上登记的经营者姓名为张三。该零售户经营场所面积约为150平方米；其营业时间从早上9点至晚上8点，周末和国家法定节假日24小时都营业；通过自选方式销售食品、药品、书籍报刊、饮料、烟酒等乘客需要的商品；引进了一套计算机管理的收银系统，顾客在收银处统一结算。经调查，张三还和李四、王五、赵六合伙，在该市城东汽车站、新家园小区开有两处相同类型的分店，并计划再在城西、城南开两处分店，最终达到五家连锁分店的规模；所有分店名称、装潢、管理都采取统一的模式。同时，还发现在张三店铺往西300米处有一书报亭，也在持证零售卷烟。 请根据以上案例回答下列问题：