[单项选择]为防止回火现象的发生,可采取的措施包括( )。 A. 冷却燃烧器头部,以降低该处的火焰传播速度 B. 燃烧器安装要正确,保证喷嘴和混合管的同心度 C. 设计燃烧器时应根据最大热负荷正确选择可见火焰传播速度及火道入口直径 D. 保证混合气体从燃烧器头部进入火道或燃烧室处的速度场分布均匀,可将头部制成扩散状
第6题: [单项选择]下列说法错误的是( ) A. 经营者以广告或产品说明书表示商品质量状况的应保证其提供的商品的实际质量与表明的质量相符 B. 经营者提供的服务,按国家规定,承担包修、包换、包退责任的应按约定履行,不得无理拒绝 C. 经营者发现其提供的商品存在严重缺陷的应立即退货 D. 经营者提供服务,按国家规定或商业惯例应向消费者出具服务单据 E. 经营者与消费者交易,应遵循自愿、平等、公平、诚实信用的原则 参考答案:C 答案解析:[知识点] 《中华人民共和国消费者权益保护法》:经营者的义务
第11题: [单项选择]His office is ______ to the President's; it usually takes him about three minutes to get there. A. related B. adhesive C. adherent D. adjacent 参考答案:D 答案解析:related to有关的;adhesive to粘性的;adherent to坚持于;adjacent to邻近的,接近的。
第29题: [单项选择]Which days doesn’t the man’s son workIn which department does Bill work now A. engineering B. sales C. customer service 参考答案:C 答案解析:[解析] Woman: Hello, Karl! How are you Man: I’m fine. Thanks. How are things at the company 第30题:[单选题]—How tall is your sister? ( ) —______( A. She is not very well. B. She is 28 years old. C. She is very nice. D. She is as tall as I am. 参考答案:D