问题 多项选择题

对于某以河水为水源的分区给水系统,下述关于分区形式选择的论述,正确的是( )。

A.若城市沿河岸发展而垂直等高线方向宽度较小,宜采用并联分区
B.若城市垂直于等高线方向延伸,宜采用串联分区
C.若城市高区靠近取水点,宜采用并联分区
D.若城市高区远离取水点,宜采用串联分区

答案

参考答案:A,B,C,D

解析:对于以河水为水源的分区给水系统,若城市沿河岸发展而垂直等高线方向宽度较小,宜采用并联分区,因并联而增加的输水管长度不大,但高、低压水泵可集中管理;相反,若城市垂直于等高线方向延伸,则宜采用串联分区,以避免输水管长度过大;若城市高区靠近取水点,宜采用并联分区;若城市高区远离取水点,宜采用串联分区,以避免高压输水管过长。

单项选择题
填空题

请根据句意用适当的介词填空。

1. Bob lives            China            his parents.

2. Hainan is far            Beijing.

3. We will leave            the afternoon            February 1st.

4. It's about 100 kilometers            this city            your city.

5. They stayed            these children            two weeks.

6. I have pairs            shoes.

7. Danny gets            the train and sits            his seat.

8. The boy is pointing             the bird            the sky.

9. What's the red thing             there?

10. I can see a big pear             the top __________ the tree.

11. How much             a bike?

12. Please take care             your clothes.

13. Are you looking             your cat? I saw it sleep in a tree.

14. Let's put a bandage             your arm.

15. Put the film             your camera, Jack.

16. Wan Hua sits             my left.

17. Please put the stamp             the top, right corner             the postcard.

18. Peter is writing some postcards             his friends.

19. We'll go there             a bus             Tuesday.

20. When did you arrive              Canada?

21. They looked             everything in the shop.

22. Can you walk             school             the big box?

23. I like playing             my dog             home.

24. — What ___________ flying kites on the playground?

      — That's a good idea.

25. This gift is             you, Dad.

26. What happened             these people?

27. Jenny and Danny are leaving             Beijing ___________ Shanghai tomorrow.

28. Could you take a picture             us?

29.             the way, I had a good time             you in Dalian.

30. Go            this street and turn left              the traffic lights.