转化炉的负压一般控制在(),它是靠引风机入口档板开度来调节的,负压小时,档板(),增大引风量,负压大时,档板(),减少引风量。
参考答案:-3~-5mmH2O柱;开大;关小
设等比数列{an}的各项均为正数,且a5a6=9,则log3a1+log3a2+…+log3a10= [ ]
A.12
B.10
C.8
D.2+log35
What the remote areas need ____ education to children and what the children need ____ good
textbooks and teachers at the moment. [ ]
A. is; are
B. are; is
C. was; were
D. were; was