[填空题]

The Nuclear Age

The Earth exploded into the nuclear age on 16 July 1945. On that day, the US tested a completely new type of weapon in the New Mexico desert. Crafted from a tennis-ball-sized plutonium sphere (钚球), the bomb produced an explosion equivalent to 20,000 tons of TNT.

Sixty years on, tens of thousands of tonnes of plutonium and enriched uranium (浓缩铀) have been produced. The global nuclear arsenal (兵工厂) stands at about 27,000 bombs. Nine countries very proba-bly possess nuclear weapons,while 40 others have access to the materials and technology to make them.

But nuclear technology has also been used for peaceful means. The first nuclear reactor to provide electricity to a national grid opened in England in 1956. Now, 442 reactors in 32 nations produce 16% of the world's electricity.

Nuclear power has been championed as a source of cheap energy. But this was weakened at the end of the 20th century by

最新试题

• ●    [判断题]站内或区间限速时，车站值班员在执行车机联控时，应主动呼叫司机。（）
• ●    [多选题]定期检查评估营业机构的操作风险及案件风险管理体系的运作情况，监督管理政策、监管要求的落实情
• ●    [单选题]截至2016年12月31日，某股票型基金规模18亿元，股票投资总市值10亿元。前十大重仓股
• ●    内存地址从4000H到43FFH，共有 (1) 个内存单元。若该内存每个存贮单元可存储16位二进
• ●    [单选题]对下列句子中加点词的解释，不正确的一项是（ ）。
• ●    简述戈尔曼的情绪智力理论。