Only when we have enough input excellent output -speaking and writing in English．( )A．did we presentB．can we presentC．present weD．we can present 题目和参考答案——青夏教育精英家教网—

16．Fifteen percent of US teenagers aged 12 to 17 who own mobile phones have received nude（裸体）or nearly nude images of someone they know，according to a survey released on Tuesday．
Only four percent of mobile phone-owning（35）Ain that age group have sent sexually suggestive pictures of themselves，a practice known as"sexting，"（36）Dthe Pew Research Center's Internet & American Life Project．
The Pew survey found that girls and boys were equally as likely to have sent a suggestive picture to（37）Bperson and（38）Cteenagers were more likely to have engaged in"sexting．"
Eight percent of 17-year-olds with mobile phones have sent a sexually provocative（刺激的） image（39）Atexting and 30 percent have（40）Ba nude or nearly nude image on their phone．
Only four percent of 12-year-olds have sent suggestive images of（41）B．
Amanda Lenhart，a senior research specialist at Pew and the author of the report，said sexually suggestive images have become a（42）Dof"relationship currency"for teens．
"These images are（43）Aas a part of or instead of sexual activity，or as a way of starting or（44）Ca relationship with a significant other，"she said．"And they are also passed（45）Ato friends for their entertainment value，as a joke or for（46）B．"
"The desire for risk-taking and sexual exploration during the teenage years（47）Cwith a constant connection via mobile devices creates a'perfect storm'for sexting，"said Lenhart．
"Teenagers have always grappled with issues around sex and（48）D，but their coming-of-age mistakes transgressions have never been so easily（49）Aand stored for others to see，"she added．
The survey found that teens with unlimited text messaging plans were more likely to receive"sexts"（50）Aimages of people they know．About 75 percent of mobile phone owning teens have unlimited plans．
Among this group，Pew said 18 percent reporting receiving"sexts"（51）Bwith eight percent of teens on（52）Adata plans and three percent of teens who pay per message．
According to Pew，58 percent of 12-year-olds own a mobile phone and 83 percent teens aged 17（53）C．
Pew noted that a number of US states are grappling with how to（54）B"sexting"among minors and some legislatures（立法机关） have stepped in to consider laws that would downgrade charges from felonies（重罪） to misdemeanors（轻罪）．
Pew conducted telephone interviews with 800 teens aged 12 to 17 and their parents between June 26 and September 24．

35．A．teens	B．adults	C．students	D．parents
36．A．referring to	B．reporting	C．saying	D．according to
37．A．other	B．another	C．others	D．the other
38．A．younger	B．fewer	C．older	D．more
39．A．by	B．in	C．on	D．through
40．A．accepted	B．received	C．sent	D．mailed
41．A．others	B．themselves	C．himself	D．herself
42．A．habit	B．system	C．method	D．form
43．A．shared	B．limited	C．tasted	D．controlled
44．A．remaining	B．gaining	C．maintaining	D．obtain
45．A．along	B．by	C．as	D．for
46．A．joy	B．fun	C．excitement	D．delight
47．A．compared	B．followed	C．combined	D．went
48．A．friendships	B．scholarships	C．relatives	D．relationships
49．A．transmitted	B．transformed	C．formed	D．switched
50．A．containing	B．concluding	C．including	D．concerning
51．A．comparing	B．compared	C．connected	D．joined
52．A．limited	B．unlimited	C．few	D．little
53．A．have	B．same	C．do	D．too
54．A．do with	B．deal with	C．remove	D．ban