【 】主要用于对数据库中的数据进行分组、计算、汇总和打印输出。

Have you ever thought, “I wish I could take a year off and just travel around the word?” Well, three lucky American teenagers were able to do just that. The teens — two males and one female — got an all-expenses paid, yearlong hike to five continents.

This trip didn’t include any five-star hotels or shopping funs. Eighteen-year-old Jamie Fiel from Keller, Texas, 17-year-old Arsen Ewing from Canyon, California, and 16-year-old Tyler Robinson from Lincoln, Massachusetts, didn’t expect fancy treatment. They signed up for the experience of a lifetime, which included hard work, often uncomfortable accommodations, and encounters with some of nature’s most dangerous animals and environments.

Jamie, Arsen, and Tyler were among hundreds of high school kids nominated by their science teachers to take this trip. Earthwatch Institute sponsored this adventure. Each year, Earthwatch employs thousands of volunteers worldwide to help with scientific research projects.

The group went all around the world to get a close look at the most pressing environmental issues of our time. Their assignments were as varied as their locations, and included measuring and attending pink flamingos in Kenya’s Great Rift Valley, and tracking giant sea turtles in Costa Rica.

As they worked with the Earthwatch scientists, Jamie, Arsen, and Tyler began to understand that we are at a critical moment in the life of our planet. Time for change is running out. As the teens went from country to country and witnessed different environmental dangers and challenges, they understood that solutions to important environmental issues start with the power of one person’s actions. They realized that each of them can make a difference.

小题1:These teenagers went on the journey around the world      .

A．to experience the most serous environmental problems on the earth

B．to bring the kindness of America to the other parts of the world

C．to go on sightseeing around the world

D．to call on more teenagers to join Earthwatch Institute小题2:What’s TRUE about their journey?

A. They had to pay for their journey on their own expense.

B, They often had to move from one hotel to another.

C. They had to take great pains to collect environmental information.

D. They received a warm welcome every time they arrived at a new place.

小题3:It can be inferred that Earthwatch Institute could be          .

A. an international university that takes in students from all over the world

B. a TV station that makes programmes on the beautiful scenery of the earth

C. a travel agency that organizes adventure trips specially for school children

依据图文材料及所学知识，完成下列问题。

下图中艾尔湖为时令湖，湖中有水时，周围绿草繁茂，一片生机勃勃的景象；湖泊“消失”时，宽阔的湖面上积上厚厚一层盐，周围草木全无，鸟兽绝迹。澳大利亚政府设想开凿一条运河把附近的海湾和艾尔湖联系起来，海水自动流向艾尔湖，使艾尔湖不再干涸。

(1)对比甲乙两区域河流水文特征的主要差异，并分析造成这种差异的原因。(8分)

(2)分析艾尔湖盆地多发沙尘暴，且高峰出现在12月到翌年2月的原因。(8分)

(3)你认为澳大利亚政府是否应该开凿海湾与艾尔湖间的运河?请从生态环境的角度说明你的理由。(合理就给分)(8分)

在用油膜法估算分子大小的实验中：

下面是一些实验步骤及注意事项：

A．配置油酸酒精溶液；

B．一定要仔细清洗浅盘，充分洗去油污、粉尘，以免给实验带来误差；

C．用注射器（或滴管）将V=1 毫升油酸酒精溶液一滴一滴的滴入量筒中，并记下滴数n，计算出每滴油酸酒精溶液的平均体积V₀=

D．向浅盘里注入适量的水，并将痱子粉（或石膏粉）从盘的中央加入，使粉尽量洒厚一些，再用注射器（或滴管）从适当高处将一滴油酸酒精溶液滴在水面上；

E．等待油酸薄膜的形状稳定后，将玻璃板放在浅盘上，画出形状，用数格子法测算出面积S；

F．根据一滴油酸酒精溶液的体积V₀和膜的面积S计算出油酸薄膜的厚度L=

G．重复实验测几次油酸薄膜的厚度并求出平均值，即可认为就是油酸分子的直径．

以上实验步骤中错误和不妥的有______（只填前面的字母）．

对连续生产稳定、污染物排放稳定的建设项目，采样和测试的频次一般不少于( )次。

A．2
B．3
C．4
D．5

2014年全区体育健儿参加国际国内重大比赛共获得多少枚金/银/铜牌？