非稳态扩散
参考答案：在扩散过程中任何一点的浓度都随时间不同而变化的扩散称为非稳态扩散。
Online shopping is increasingly popular；by September 2011，the total daily sales at Taobao______ had amounted to 935 million yuan，which had even overtaken the daily total sales of Hong Kong.
A．just
B．only
C．merely
D．alone
下列属于成品腻子的是( )。
A．原子灰
B．硝基腻子
C．血料腻子
D．油性自调腻子
