当蒋礼决定是否多提供一个小时的劳动时，她比较（）。

A:多一小时收入的边际收益和总收益 B:多一小时收入的总收益和总成本 C:多一小时的收入的边际收益和边际成本 D:多一小时收入的绝对和相对优势

练习瑜伽之前几小时左右洗冷水澡最佳（）

A:半小时 B:一小时 C:二小时 D:三小时

个别督导的时间一般每次( )。

A:一至二小时 B:二至三小时 C:半小时至一小时 D:一至一个半小时 E:一小时左右

团体督导的时间一般每次( )。

A:一至二小时 B:二至三小时 C:半小时至一小时 D:一至一个半小时 E:一小时左右

下列句子没有语病的一项是（ ）

A: 通过这次活动，使我们开阔了眼界，增长了知识。 B: 中央工艺美术学院的每一个大学生将来都希望自己成为一个出色的美术家。　　 C: 我用了整整一小时左右，才写完了这篇作文。　　 D: 正是这双布满老茧的手，不断刷新国内外记录，展现了当代工人崭新的风貌。

根据提示，写一篇120-150词的英语作文。(不必逐句翻译）

为地球熄灯一小时

Initiated in Australia in 2007, Earth Hour is a time zone-by-time zone plan in which people around the world are encouraged to switch off  their lights for 60 minutes on the last Saturday night of March to show their concern about global warming and climate change.The campaign aimed to send out more and clearer messages to world leaders before they meet in Copenhagen in December to have a new global impact on curbing emissions of greenhouse gases. The UN Climate Panel says greenhouse gas emissions are warming the planet and will lead to more floods, droughts, heatwaves, rising sea levels and animal and plant extinctions. World emissions have risen by about 70 percent since the 1970s.

In Shanghai, China's financial hub, floodlights to illuminate some 160 buildings , including the world's third tallest TV tower "Oriental Pearl" and the 492-meter-tall World Financial Center, also went down. Skyscrapers with glowing windows dominating the night skyline are usually considered symbols of modernization in China. But Saturday night, going dark became trendy.

     In many Shanghai outlets of international fast food chain KFC, people enjoyed candle-lit dinners after the restaurants dimmed lights.

     As everybody can see, this will send an important message to the world that people in China are becoming more aware of climate change issues. It's a very special night because it sends an environmental message to us,too. We hope such an activity will inspire everyone to make energy saving a daily habit.

   But in spite of this, not everyone is so convinced and agreeable. Some consider it a show for the moment. But I strongly support this kind of activity which may arouse people's concern about the environment by using less power .It is true that Earth Hour is just for one hour each year. One person may be small, but we can make difference if we work collectively to change our own behaviors.

    Anyway,  the action showed millions of people want governments to work out a strong new U.N. deal to fight global warming , even though the global economic crisis has raised worries about the costs. We have been dreaming of a new climate deal for a long time. Now we're no longer so alone with our dream. We're sharing it with all these people switching off  their lights.

地面辐射差额是指地面辐射能的收入与支出之差。而辐射差额数值的大小，又可反映温度升降程度。据此，完成题。一日之内，辐射差额由负值转为正值的时间是（ ）

A:日出后一小时左右 B:日落前一小时左右 C:正午12时 D:子夜0时