只适用于蒸汽、空气等清洁介质,不能安装在液体管道上,使用时还应特别注意压力范围的阀门是()。
A.安全阀
B.节流阀
C.蝶阀
D.减压阀
参考答案:D
根据对话意思和所给首字母,写出完整正确的单词。
Betty: Well, it's great to be here in Beijing.
Helen: Yes, it's exciting. Lots of 1. c______ take place every day.
Betty: And the Olympics are coming. I think Beijing is really the place to be right now.
Helen: Yes, 2. m______ people are curious about Beijing than before. They all want to see it themselves.
Betty: Beijing is really a great city. But there are also some problems, such as pollution and 3. c______ traffic.
Helen: You're right. There are a lot of challenges (挑战).
Betty: So our government has started "The Green Olympics Action Plan" to 4. b______ Beijing
into a better place to live in.
Helen; That sounds great. We all 5. h______ the Olympics will be a great success.
存在于豆类食物中的寡糖主要是()。
A.棉子糖
B.糊精
C.乳糖
D.半乳糖
E.木糖