(mathematics 数) number which can be divided exactly only by itself and
1 (eg 7, 17, 41) 质数, 素数（只能被1和这个数本身整除的数, 如7、17、41）.
a number that can be divided only by itself and the number one. For example, three and seven are prime numbers.
1. Every year, on Independence Day, our Prime Minister Nehru spoke of the benefits of science and technology. 每年的独立日，我们的总理尼赫鲁都要讲一讲科学技术的好处。
2. Each person generates about 4.4 pounds of garbage a day — a number that has seen steady growth. 每人每天生产的垃圾大约为4.4磅，这一数字仍在持续增长。
3. But, in addition to that basically simple concept, the bank and its customer owe a large number of obligations to one another. 除了这一基本的简单的概念外，银行和储户彼此还需承担大量义务。
4. But other suns, stars as the astronomers call them, are bound to have planets like our own, and as the number of stars in the universe is so vast, this possibility becomes virtual certainty. 但是，其他的太阳，既天文学家所说的恒星，肯定会有像我们地球一样的行星。因为宇宙中恒星的数目极其庞大，所以存在着产生生命星球的这种可能性是肯定无疑的。
5. Because the tree was mentioned in a newspaper, the number of visitors to Frinley has now increased. 就因为报上提到过这棵树，所以现在来弗林利参观的人越来越多。
6. By a quirk of fate, Humboldt and Bonpland met Mariano Luis de Urquijo, Prime Minister of Spain, who was able to obtain for them the permission to visit the Spanish empire in South America. 由于命运的安排，洪堡和庞普朗遇到了西班牙首相乌而吉乔，他可以使他们得到前往南美洲的西班牙帝国去访问的许可。
7. But since then the park has been hit by a number of problems. 但那以后，这个主题公园遇到了一些问题。
8. We owe a lot to the birds and beasts who eat insects but all of them put together kill only a fraction of the number destroyed by spiders. 我们要十分感谢那些吃昆虫的鸟和兽，然而把它们所杀死的昆虫全部加在一起也只相当于蜘蛛所消灭的一小部分。
9. What invariably happens is that a great number of things choose to go wrong at precisely the same moment. 情况经常是这样的，许许多多的事情都偏偏赶在同一时刻出问题，
10. We had spent several days in a small town and visited a number of old churches in the vicinity. 我们在一座小镇上逗留了几天，参观了附近的许多古老的教堂。