关于滤过的影响因素错误的表述有

A．操作压力越大，滤过速度越快，因此常采用加压或减压滤过法

B．滤液的黏度越大，则滤过速度越慢

C．滤材中毛细管半径越细，阻力越大，不易滤过

D．由于Poiseuile公式中无温度因素，故温度对滤过速度无影响

E．滤速与滤材的毛细管的长度成正比

The development of e-commerce may well bring the world into a brand new era of "electronic currency". At the moment, (51) areas in Europe, the United States and Asia have already started studying the possibility of an electronic currency. Electronic currency is not only about currency. It (52) to an entire finance system on the Net. It includes a virtual numeric currency, an electronic system of withdrawals, transfers and loans, and (53) cards of all shapes and sizes. The (54) of an electronic currency system implies the emergence of "virtual banks" and "virtual enterprises". Actually, the first virtual bank appeared in the US in 1995. (55) it is a small and insignificant bank, it represents the trend of the future. In time to come, we may even have to (56) the familiar paper currency.

As the Net pushes the economy (57) rapidly, the economy is also bringing the Net market forward, resulting in the Internet itself becoming the world’s largest emerging market. Of course, this is just the beginning. Although there are many companies which made huge profits (58) in the Internet market, they tend to be small companies. To date, most companies are making losses. The competition in the knowledge-based economy will also be more (59) This will definitely promote (60) and more efficient cooperation.

57().

A.ahead 

B.backward 

C.front 

D.behind