导游人员在讲解时，会将哪一位置视为最佳位置（） A.合作位置 B.交流位置 C.争位

如图，等边△ABC的边长为2cm，D、E分别是AB、AC上的点，将△ADE沿直线DE折叠，点A落在点A′处，且点A′在△ABC外部，则阴影部分图形的周长为（    ）cm。

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When Joe Bates was twelve years old, he lost interest in school. He stopped listening in his classes. Some of his teachers began to consider him a problem.

But a few of Joe’s teachers thought that Joe might have lost interest in schoolwork because he already understood it. They proposed that Joe try taking a university class in computer science. Joe did. He was the best student in the class. Later tests showed that his intelligence and knowledge were far greater than most children of his age. He entered university when he was thirteen, about four years earlier than most children. And by the time he was in his early twenties, Joe was teaching computer science at a university.

Joe’s story shows what can happen when a child’s unusual ability is recognized. Sadly, however, not all gifted children get this recognition. And educational experts say unusually gifted children may waste their abilities if they do not get help to develop them.

Studies show that almost twenty percent of students who fail to complete high school in the United States are gifted children.This is because gifted children can have special problems as well as special abilities. Teachers may not recognize their abilities or may not know how to keep them interested. Or they may consider such students to be troublemakers or rebels.

Gifted children may feel lonely or different because they do not know other children who share their interests.

Educators say there are more than two million gifted children in the United States today.  But they say fewer than half are taking part in special education programs designed for them.

One of the most successful programs is held every summer at John Hopkins University in the state of Maryland, where Joe Bates went to school. It started in 1980 when educators saw that there must be many children like Joe.

At first, only 100 children took part in it, and now more than 1,000 children between the ages of nine and sixteen are students in the summer program.

The John Hopkins program provides studies in math and science. It also has classes for children with unusual ability in language and writing. The children study the same subject every day for several weeks. It could be biology, or history, or literature. In those few weeks, they learn as much as in a normal nine-month school year.

William Durden, the director says the program succeeds because it permits children to make progress more quickly than in a traditional program. And the children get to meet others like themselves.

49. Joe Bates stopped listening in his classes because __________.

A. he lost interest in school

B. he hated those teachers who considered him a problem

C. he had already understood what he was taught

D. he wanted to take a university class

50. When a child’s unusual ability is recognized, __________.

A. he can do whatever he likes

B. he will no longer be considered to be a troublemaker or rebel

C. he may have more success than most children of his age

D. he will certainly take part in a special education program

51. According to the passage, the most important thing is to __________.

A. recognize and develop gifted children’s unusual abilities

B. design and support special education programs for gifted children

C. help gifted children get to meet others who share their interests

D. encourage gifted children instead of treating them as a problem

52. Many gifted students fail to complete high school in the United States because _________.

A. they take part in traditional education programs

B. their unusual abilities are not recognized 

C. their teachers don’t know how to keep them interested in schoolwork

D. they have special problems as well as special abilities.

判断成人心跳停止最简单的方法是（）

A.看心前区起伏

B.触摸颈动脉搏动

C.触摸桡动脉搏动

D.触摸足背动脉搏动

E.触摸肱动脉搏动

某地区选聘近200名高校毕业生到村（社区）担任村官，享受全额拨款事业单位绩效工资待遇，做到“以绩取酬”。实行事业单位绩效工资（）

①是社会主义分配原则的重要体现

②有利于提高事业单位所有劳动者的收入

③实现了按劳分配与按生产要素分配的统一

④能够完善分配激励机制，调动劳动者积极性

A.②④

B.①③

C.②③

D.①④

为证明光照和重力两种因素对生长素在植物体内的分布哪个影响更大，某研究性学习小组进行如下探索：

材料用具：品种、大小相同的泡胀玉米种子若干，空易拉罐四个，沙土，不透光的牛皮纸等。

方法步骤：

（1）取四个空易拉罐，分别剪去顶盖，装入湿润沙土并分别标号（甲、乙、丙、丁）；在每个易拉罐内植入三颗玉米种子，放在温度适宜的阴暗处培养，待苗长到2㎝左右时备用。

（2）将甲、乙、丙、丁均用不透光的牛皮纸包严（留出幼苗生长的足够空间），放在实验台上，甲、乙直立放置，在乙装置的一侧开直径l㎝左右的小口，在它们的侧面O．5m处用lOOW的白炽灯连续照射；丙、丁水平放置，在丙装置的正对地面处开直径l㎝左右的小口，在它们的下方0.5m处用lOOW的白炽灯连续照射（装置如图所示）；甲、乙、丙、丁的其他条件相同且适宜。

实验现象：两昼夜后，如图所示。甲直立生长；乙向光弯曲生长；丁向上弯曲生长；丙也向上弯曲生长，但与丁相比，丙弯曲度要小一些。

由乙、丙、丁装置内的玉米苗生长情况可知（）。