烧结矿转鼓指数级别范围：一级品≥（）%，二级品≥（）%。
参考答案：72；70
_____ in time for Christmas，all these gifts must be mailed immediately
A．So as to be received
B．In order to receive
C．So as to be receiving
D．In order to be received
三个连续自然数，中间的是n，那它前边的数是______，后边的数是______．
