采用固定式泡沫灭火系统时,除设置固定式泡沫灭火设备外,同时还应设置泡沫软管.泡沫枪和泡沫消防车等()泡沫灭火设备。
A、固定式
B、移动式
C、半固定式
D、综合式
参考答案:B
阅读理解
Hello! I'm Susan. Look at this picture. You can see a big sofa next to (在…附近) the wall. My
parents like to sit on it to read books (看书), and sometimes (有时候) they meet some friends there.
There are two plants near the sofa. They're nice. What's that on the wall? Oh, it's a new TV. I often
watch TV on weekends (周末). Can you see some fishes (鱼) in that big box? I like to play with them
after school (放学后). Where's my dog Billy? Is it on the floor? No, it's under a chair! Do you like it?
1. Susan's parents _____ on the sofa.
A. watch TV
B. play with fish
C. read books
D. meet friends
2. What's the dog's name?
A. Susan.
B. Billy.
C. I don't know.
D. It doesn't have a name.
3. _____ are near the sofa.
A. A new TV
B. A big box
C. Some fishes
D. Two plants
在分布式数据库系统中,逻辑数据库被划分成若干片段,其中按投影操作来分片的称为
A.水平分片
B.垂直分片
C.导出分片
D.选择分片