在高层建筑的消火栓系统中,根据楼层不同,往往要在消火栓前加装不同孔径的孔板,这个孔板有何作用?
参考答案:
孔板仅有减动压的作用,一般仅用于消火栓前或喷淋支管段。
看看你的应变能力,用所给单词的适当形式填空。
1.I can’t find the museum. What _____ I _____(do)?
2.I’m sorry I didn’t finish _____(write)my composition.
3.What time _____ Li Lei _____(get)up this morning?
4.Could you please _____ (pass)me those dumplings?
5.Mr White isn’t used to _____ (drink)tea.
6._____ we _____ (need) to buy some more chicken, mum?
7.Don’t let the students _____ (suffer)from lots of homework.
8.We have to _____ (get)there earlier than eight o’clock.
9.We’d like you _____ (play) volleyball with us.
10.I’m very upset and don’t know what _____ (do).
患急性肾炎的病人,验尿时,若发现尿液中有红细胞和蛋白质,则发生病变的部位是
A.肾单位
B.肾小球
C.肾小囊
D.肾小管