题干

某市今年中考理化实验操作考试,采用学生抽签方式决定自己的考试内容.规定每位考生必须在三个物理实验(用纸签A、B、C表示)和三个化学试验(用纸签D、E、F表示)中各抽取一个实验操作进行考试,小刚在看不到纸签的情况下,分别从中各随机抽取一个.用列表或画树状图的方法求小刚抽到物理实验B和化学实验F的概率.
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答案(点此获取答案解析)

解:

化学实验

物理实验

D

同类题3

阅读材料,完成下列要求。

材料一:(1900年前后)帝国主义(指欧洲国家——也包括后来的日本和美国)对世界的控制有时这种控制是通过旧的手段——例如武力完成的。但是,更为经常的是通过贸易、投资和商业活动,使列强从殖民地获利,在不直接进行政治控制的前提下,影响殖民地的事务。

——摘编自【美】杰里·本特利《新全球史》

材料二;二战进行中,罗斯福逐渐形成了以“非殖民”原则为基础的世界秩序构想。1953年,美国针对殖民地问题提出中间道路。即在殖民主义(者)与民族主义(者)之间采取中间立场;既不放弃外交中的反殖民主义传统,又要支持欧洲盟国;既不放弃传统的道义利益,又贯彻反苏反共的冷战总目标。50年代中期后,随着第三世界的形成,苏联在第三世界和殖民地的影响日益加强,以及联合国会员国结构发生巨大变化,“中间道路”政策在联合国遭遇挫折。1960年第15届联大会议中,苏联等43个亚非国家一起向联大提出《非殖民化宣言》,要求彻底结束殖民主义。该提案得到了联大成员半数以上支持,西方国家成为少数派。美国与英法比等国几次协商,先后三次更改投票立场,最终在投票前不得不再次更改立场。美国频繁更改的投票立场表明,“中间道路”陷入困境。

——摘编自毕元辉《“中间道路”及其困境:1945-1960年美国“非殖民化”政策评析》

材料三:20世纪80年代,以美苏关系的重大转折为契机,短短10年间世界格局的演变注入了一股突如其来的力量。此次世界格局的转换不像以往那样发生在大规模战争之后,新体制的确立缺少硬性的仲裁力量。此外,由于多极化趋势的长期酝酿和发展,当旧格局最终被打破后,多种基于民族主义的国家和地区性力量亦趁势蜂起,谋求在新格局中的位置和利益。

——摘编自王斯德《大学世界史》

同类题4

根据短文理解,选择正确答案。

    Coffee drink is widespread. When people argue about whether coffee is good for health, they're usually thinking of the health of the coffee drinker. Is it good for your heart? Does it increase blood pressure? Does it help you concentrate? However, coffee affects the health of the human population in other ways, too.

    Traditionally, coffee bushes were planted under the shade of taller trees. However, more and more farmers in Latin America are deforesting the land to grow full sun coffees. At first, this increases production because more coffee bushes can be planted if there aren't any trees. With increased production come increased profits.

    Unfortunately, deforesting for coffee production immediately decreases the local wildlife habitat, because native birds nest and hide from predators(捕食者)in the tall trees and migrating birds rest there.

    Furthermore, in the long term, the full-sun method also damages the ecosystem because more chemical fertilizers and pesticides(杀虫剂)are needed to grow the coffee. The fertilizers and pesticides kill insects that eat coffee plant, and then the birds eat the poisoned insects and also die. The chemicals kill or sicken other animals as well, and can even enter the water that people will eventually drink.

    Fortunately, farmers in Central and South America are beginning to grow more coffee bushes in the shade. We can support these farmers by buying coffee with such labels as "shade-grown" and "bird-friendly".

    Sure, these varieties might cost a little more. But we're paying for the health of the birds, the land, ourselves, and the planet. I think it's worth it.