题干

已知cos(x﹣ π
3
)=
1
3
,则cos(2x﹣ π
5
3
)+sin2π
3
﹣x)的值为(   )

A:﹣ 19

B:19

C:53

D:﹣ 53

上一题 下一题 0.0难度 选择题 更新时间:2017-05-19 03:27:49

答案(点此获取答案解析)

C

同类题2

   “I sometimes get up at three or four in the morning and I surf the net.”
   “I often check my e-mail forty times a day.”
   “1 often spend more than three hours during one time on the net."
   “I spend more time in chat rooms(聊天室)than with my‘real—life’friends.”
   Do you know who like these? They are part of a new addiction(瘾)called Internet addiction. Internet addicts spend at least thirty to forty hours online every week.The use of the Internet can be an addiction like drug(毒品)use.People lose control(控制)of the time they spend on the Internet.
   For example, one college student was missing for several days.His friends were worried.and they called the po1ice.The police found the student in the computer lab:he was surfing the net for several days straight.
   Studies show that about 6%to 10%of Internet users become addicted.And people worry about the teens because the Internet is changing the playing field for some of them.They spend more time in cyber—space than in the real world of friends and family.
   Is“surfing the net”a hobby or an addiction for you? You may have a problem if you have these symptoms(症状)
●You do not go to important family activities or you do not do school work because you like to spend hours on the Internet.
●You can’t wait for your next online time.
●You plan to spend a short time online,but then you spend several hours.
●You go out with your friends less and less.

同类题3

阅读下面文言语段,完成下面小题

    赵希乾,南丰东门人,幼丧父,以织布为业。年十七,母抱病月余,日夜祈祷身代,不少愈。往问吉凶于日者,日者推测素验,言母命无生理。又往卜于市,占者复言不吉。希乾踟蹰不去,曰:“何以救母病?”占者恶其烦数,曰:“汝母病必不治,若欲求愈,无乃割心救之耶?”希乾归,侍母左右,见病益危笃。时日光斜射床席,形影孑立,寂寂旁无一人。希乾忽起去,笥中得薙发小刀,立于窗外,剖胸,深寸许,以手入取其心,不可得。忽风声震飒,门户胥动,以为有人至。四顾周章,急取得肠,抽出,割数寸。盖人惊则心上忡,肠盘旋满胸腹云。希乾置肠于釜上,昏仆就室而卧。顷刻,母姑来视病,见釜上物,以为希乾股肉也,烹而进之母。再视希乾,则血淋漓心腹间,不能出声,始知希乾为割心矣。

    赵氏故宋裔,为南丰巨族。宗党以为奇孝,供赡其母子,而更教之读书。学使者侯峒曾闻其事,取充博士弟子员。崇祯壬午,以恩诏天下学,选一人贡于成均。学使者吴石渠,既考试毕,进诸生而告之曰:“百行以孝为先。赵希乾割心救母,不死,不可以寻常论。建武多才,校士衡文,希乾不应入选。今欲诸生让贡希乾,以示奖劝。”诸生咸顿首悦服。于是以希乾选补壬午恩贡。又三四年而有甲申、乙酉之变,希乾避乱山中,将母不遑,遂卖卜,逃走于四方,以养其母。又十余年,母寿八十余而卒。

    予自幼时常见希乾过先君谈,饮食起居如常人。面黎黝,高准方耳,睛光满眸子,颀然而长,多浑朴之风。自是希乾少家居。母死未十年,而希乾亦卒,年六十一。

    甘表曰:朝廷不旌毁伤愚孝,尚矣。然希乾一念之诚,若有以通天地、格神鬼也,岂不可嘉哉?汤公惕庵最恶言希乾事,予则以为应出特典,一加旌赏。盖事不可法而可传使知孝行所感虽剖胸断肠而不死岂非天之所以旌之耶天旌之谁能不旌之?然旌而不传,不若不旌而传也。安得龙门之书以施于后世哉?呜呼,古今忠孝之士,非愚不能成。而世之身没而名不传者,又何多也?悲夫!