在25 ℃时，将两个铂电极插入一定量的硫酸钠饱和溶液中进行电解，通电一段时间后，

E—schoolbags

Is your schoolbag too heavy to carry? The e-schoolbag will help you. It is said that e-schoolbags are going to be brought into use in Chinese middle schools soon.

Heavy schoolbags have been a serious problem for a long time. But the e-schoolbag will work it out. An e-schoolbag is much lighter than a usual schoolbag. Perhaps, the e-schoolbag should be called an e-textbook. It is as small as a usual book, but it can still have all the things for study, such as a textbook, an exercise book and so on. They can be made into chips(芯片) like stamps. The students can read the text page by page on the screen, take notes, or even send e-mails to their teachers. They only need to put the right chip into the e-schoolbag and then the students can use it.

Some people say that e-textbooks can be easily broken, while others say it is not good to student’s eyes. But only time will tell.

小题1:What is the e-schoolbag used for ? It can’t help students _________.

A．take notes

B．send e-mails

C．lighten(减轻) the schoolbag

D．read the text in the paper book小题2:What’s the e-school like?

A．It’s bigger than a usual book.

B．It’s just as big as a usual book.

C．It’s as big as a stamp.

D．It’s not as small as a usual book.小题3:How can e-schoolbags have all the things for study?

A．They are made into stamps

B．They are made into chips.

C．They are called e-textbooks

D．They put the books into e-schoolbags.小题4:Which statement is NOT true according to the passage?

A．That e-schoolbags may be easily broken

B．It may not be good to student’s eyes.

C．They have been into use in school in China.

D．The e-schoolbag will solve the problem of the heavy schoolbags.

何谓转胞？能导致转胞的原因主要有哪几方面？

用一根长是10米的绳子围着一根树绕4圈，还余3.72米．这棵树的直径是多少米？

发达国家对发展中国家的经济战略有它的“三部曲”。第一部是输出产品，第二部是输出资本，第三部是输出牌子。输出牌子就是要在中国市场上进一步打响他们的牌子，同时压倒中国的牌子，并起到“征服人心”的作用。如果中国广大消费者更多地认同外国牌子，则民族工业必将遇到难以克服的困难。这段话主要支持了这样一种论点，即( )。

A．“品牌”比产品质量更重要

B．发达国家的“牌子”输出对我国民族工业威胁最大

C．外国产品的质量远远优于国内产品

D．发达国家总是要对发展中国家进行经济侵略