因________和________发育较早,故常先发生鼻窦炎;________和________一般在2~3岁后才开始发育,故较迟发生鼻窦炎。
参考答案:上颌窦‖筛窦‖额窦‖蝶窦
All the guests at the party were dancing and singing happily _____ the electricity was cut off.
A.until
B.while
C.when
D.because
锅炉辅机基础进行二次灌浆时,需灌浆的地脚螺栓底端不应与孔底、孔壁相碰,螺栓与孔底的最小间距应不小于()mm。
A、60
B、80
C、100