EMore than 20 Internet service providers in China have joined hands to crack_down_on junk

E
More than 20 Internet service providers in China have joined hands to crack_down_on junk mail that has long plagued（折磨, 使苦恼）e-mail users in China by establishing a coordinated （协调）group, the China Daily reported Tuesday．
The union, connecting such big fish as Sina and 263．net, has agreed to share information on technical solutions, promote public involvement and extend international cooperation, said the newspaper．
The group was collecting information from netizens（网民） on junk e-mail addresses and contents．
We will then examine the information, leading to the formation of a blacklist that can help block spam （垃圾邮件）sources, Jiang said．
He added that software solutions will also be developed to make it easy for net users to block and delete spam themselves．
But some Internet experts voiced warning, saying junk mail problems will continue to appear in the years ahead, according to the newspaper．
There are still loopholes（漏洞） in legal, managerial and technological terms which have not yet been patched up, said Qing Sihan, an information security technology specialist from the Chinese Academy of Sciences．
China has had surprising growth in Internet users with their number reaching 45．8 million by this June, ranking the second largest cyber community in the world after the United States, according to the paper．
But netizens are increasingly attacked with junk e-mails．
On average, a Chinese net user is troubled by 350 junk e-mails each year．One out of every two e-mails they receive is spam, according to China Internet Network Information Center．
73．The underlined phrase “crack down on”（in Paragraph 1）probably means “ ．”
A．make full use of B．take severe measures against
C．get rid of D．make a careful study of
74．The group was collecting information from netizens on junk e-mail addresses and contents to ．
A．ask for international cooperaton B．put the trouble-makers in prison
C．prevent the spread of junk e-mail D．warn people of the danger of using Internet
75．From the passage we know that ．
A．Sina and 263．net keep many big fish
B．Sina and 263．net are big Internet service providers
C．China owns the largest Internet user in the world
D．very few e-mails that people receive are spam73---75 BCB

(答案→)73---75 BCB 解析：73．B猜词题。根据第一段内容，垃圾邮件既然给人们长期以来造成麻烦，所以20多家提供商联手对其采取强有力的措施。74．C根据第四段的…examine the information,leading to the formation of a blacklist that can help block spam source．和第五段的…block and delete spam themselves可知答案。75．B主旨题。第一段说20 Internet service provders 联手，通过建立协调组来解决垃圾邮件问题第二段和第三段中的the union 和group同指协调组，可推出答案。

我明天再问问老师，叫他解释下这个问题