题干

图中有(  )个三角形?

A:4

B:21

C:27

D:30

上一题 下一题 0.0难度 选择题 更新时间:2012-08-07 01:46:27

答案(点此获取答案解析)

C

同类题1

阅读下文,完成下列小题。

1℃值多少钱

      ①人们在日常工作生活中,对环境温度升降1℃,似乎不太关心,但是气象经济学家发现,气候变化1℃,不仅事关全球气候变化,还跟经济发展、农业生产、环境变化、社会生活息息相关。

      ②美国气象学家对全球平均气温变化1℃的评价是:气温上升1℃,经济效益也跟着上升;气温下降1℃,经济效益也跟着下降。世界平均气温下降1℃,全球产值就减少70亿美元。

      ③气温变化1℃,对世界农业生产的影响是惊人的。据估计,农业生产区气温每下降1℃,就会减少一周(7天)的生长季。中国气候学家张家诚研究论述了气温升降1℃,对中国粮食作物的影响。气温变化1℃时,中国华南因全年的日平均气温基本上大于10℃,故积温变化为365℃,这可种植三茬作物,相当于每一茬作物有122℃的积温变化。据测试,气温变化1℃,大体相当于农作物变化一个熟级。每变化一个熟级,产量变化10%,意即气温上升或下降1℃,粮食产量均具有增产或减产10%的潜力。例如,我国著名商品粮生产基地——东北地区,若当年出现了“凉夏”,则粮食肯定减产200亿至300亿斤。反之,若出现了“热夏”,则粮食可多收几百亿斤。

      ④经济学家也发现,酷夏可激发人们消费热,促进经济发展。若夏季平均气温偏高1℃,则35℃以上的高温天数就会飙升,空调器、电风扇、纸扇、冷饮、啤酒等销售量就会成倍增多,商家无不拍手称快。

      ⑤气温升高1℃虽然会使经济增长,农作物增产,但是它所带来的环境及社会问题也着实令人担忧。联合国有关机构最新报告预测,假若全球温室气体减排计划得不到有效的实施,21世纪全球的平均气温将上升1.8℃至4℃。如此下去,人类总有一天会掉进自掘的“热陷阱”里而不能自拔。

      ⑥专家预测:由于气温上升,到2030年,我国黄河和内陆河地区的蒸发量可能增长15%左右,北方水资源短缺情况会更加严重,南方旱涝等灾害出现频率也会增加。

      ⑦德国刑侦专家研究发现:每年3月犯罪率开始上升,到7至8月可达顶峰,9月开始下降。统计分析:每当气温升高1℃,犯罪率上升15%,气温达37℃,碰到红灯待停时间长,司机间争吵比气温32℃时,高出达30%以上。

      ⑧气温变化1℃还与人的死亡有关。如上海市在炎热日(≥34℃以上),夜间气温每升高1℃,死亡增加8人;午后每升高1℃,死亡增加10人。广州市炎热日最高气温的时候,每升高1℃,死亡增加2.3人;炎热日最低气温每升高1℃,死亡增加1.5人。

      ⑨综上所述,1℃对我们人类的影响实在不可低估。

同类题4

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。

    It's natural for all kids to worry at times, and because of personality differences, some may worry more than others. ____ They typically worry about things like grades, tests, their changing bodies, fitting in with friends, the goal they missed at the soccer game, or whether they'll be bullied (欺负), or left out. Luckily, parents can help kids manage worry and deal with everyday problems.

    To help your kids manage what's worrying them:

    Find out what's on their minds.

    Be available and take an interest in what's happening at school, on the team, and with your kids' friends. ____ As you listen to stories of the day's events, be sure to ask about what your kids think and feel about what happened. Sometimes just sharing the story with you can help lighten their load.

    ____

    Being interested in your child's concerns shows they're important to you, too, and helps kids feel supported and understood. Reassuring (令人安心的) comments can help—but usually only after you've heard your child out. Say that you understand your child's feelings and the problem.

    Guide kids to solutions.

    ____ When your child tells you about a problem, offer to help come up with a solution together. If your son is worried about an upcoming math test, for example, offering to help him study will lessen his concern about it.

    Offer reassurance and comfort.

    Sometimes when kids are worried, what they need most is a parent's concern and comfort. ____ It helps kids to know that, whatever happens, parents will be there with love and support.

A. Show you care and understand.

B. Take casual opportunities to ask how it's going.

C. It might come in the form of a hug or time spent together.

D. Kids sometimes worry about things that have already happened.

E. Not all the kids worry about their teachers when they start a new school.

F. What kids worry about is often related to the age and stage they're in.

G. You can help reduce worries by helping kids learn to deal with challenging situations.