Johnson said that the evening party would cost him 200 dollars. But the expense ________ was 300 dollars.
A. really
B. true
C. actual
D. certain
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When the holiday starts, I will try ________ my research ideas.
A. out
B. in
C. with
D. up
利用膜将水中的物质( )出去的方法称为水的膜析处理法
A. 渗析
B. 纳滤
C. 超滤
D. 分离
CA膜表皮层结构致密,孔径为( ),厚约 ( ),起脱盐的关键作用
A. 0.8~1.0nm,0.25μm
B. 1.8~2.0nm,0.25μm
C. 2.8~3.0nm,0.15μm
D. 3.8~4.0nm,0.35μm
表皮层下面为结构疏松、孔径为( )的多孔支撑层
A. 100-400nm
B. 10-100nm
C. 1-40nm
D. 20nm