、 同种材料,孔隙率较大者的抗渗性和抗冻性()。
Goods are carried by several of transport--on road or rail, by sea or air.
You can _____ some bottles of wine, or some chocolates, or a bunch of flowers.
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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