对于一个稳态的流动传热现象而言,其准数方程式可表示为()。
参考答案:Nu=f(Re,Pr,Gr)
读西亚地区图,完成下列各题。
(1)一般把_______人占多数的国家称阿拉伯国家。图中虚线部分表示的是西亚的非阿拉伯国家,但有一个没表示出来,它长期以来与巴勒斯坦冲突不断,节水农业闻名世界,这个国家是__________。
(2)该区域具有世界意义的自然资源是________,主要分布在B_______(海湾)及其沿岸地区,沿岸国家A__________是重要的生产国。
(3)该区域主要的自然环境特征是__________,所以_______资源是当地生活和发展生产的限制性因素,农业分布于河谷平原和沙漠中的绿洲。_________是西亚主要的灌溉农业区。
(4)长期以来,西方强国一直将西亚作为激烈争夺对象,主要是因为西亚______________。
Have you ever heard of “3G”? Third-generation(代) mobile phone, known as 3G are popular recently. Users can surf the Internet and enjoy videos on their phones. Firstly, for some forgetful people, they will get into trouble if they forget some important things. Now you don’t need to (__小题1:____) it any more. A 3G phone can receive video news programs and messages. Secondly, you are never afraid of losing your way home. 3G phones offer map services so that they can (__小题2:____) just by pressing(按) a few keys on your phone. The most important part of the 3G technology is video calling. You can (_小题3:____) your friends and family face to face on your phone.
It’s believed to bring people convenience in their daily lives.