Idon'tbelieveasinglewordhesays.
1 for 因为,由于:表明附加或推断的理由,引导的分句前常有逗号,分句不可放句首:He must be ill,for he is absent today.他一定病了,因为他今天缺席了.所以不选A 2 动名词表伴随与谓语动词同时发生,用一般时,如发生在谓语动作之前时则用完成式having done这里是表示伴随状况 与前面的woke,left 是一连串发生的动作 ,一般认为无先后顺序
...hehiredaninterpreterwhenhevisitedbeijing.a.forbeingunableb.unable...
What is an Integrated Circuit? BackgroundAn integrated circuit, commonly referred to as an IC, is a microscopic array of electronic circuits and components that has been diffused or implanted onto the surface of a single crystal, or chip, of semiconducting material such as silicon. It is called an integrated circuit because the components, circuits, and base material are all made together, or integrated, out of a single piece of silicon, as opposed to a discrete circuit in which the components are made separately from different materials and assembled later. ICs range in complexity from simple logic modules and amplifiers to complete microcomputers containing millions of elements.The impact of integrated circuits on our lives has been enormous. ICs have become the principal components of almost all electronic devices. These miniature circuits have demonstrated low cost, high reliability, low power requirements, and high processing speeds compared to the vacuum tubes and transistors which preceded them. Integrated circuit microcomputers are now used as controllers in equipment such as machine tools, vehicle operating systems, and other applications where hydraulic, pneumatic, or mechanical controls were previously used. Because IC microcomputers are smaller and more versatile than previous control mechanisms, they allow the equipment to respond to a wider range of input and produce a wider range of output. They can also be reprogrammed without having to redesign the control circuitry. Integrated circuit microcomputers are so inexpensive they are even found in children's electronic toys.The first integrated circuits were created in the late 1950s in response to a demand from the military for miniaturized electronics to be used in missile control systems. At the time, transistors and printed circuit boards were the state-of-the-art electronic technology. Although transistors made many new electronic applications possible, engineers were still unable to make a small enough package for the large number of components and circuits required in complex devices like sophisticated control systems and handheld programmable calculators. Several companies were in competition to produce a breakthrough in miniaturized electronics, and their development efforts were so close that there is some question as to which company actually produced the first IC. In fact, when the integrated circuit was finally patented in 1959, the patent was awarded jointly to two individuals working separately at two different companies.After the invention of the IC in 1959, the number of components and circuits that could be incorporated into a single chip doubled every year for several years. The first integrated circuits contained only up to a dozen components. The process that produced these early ICs was known as small scale integration, or SSI. By the mid-1960s, medium scale integration, MSI, produced ICs with hundreds of components. This was followed by large scale integration techniques, or LSI, which produced ICs with thousands of components and made the first microcomputers possible.The first microcomputer chip, often called a microprocessor, was developed by Intel Corporation in 1969. It went into commercial production in 1971 as the Intel 4004. Intel introduced their 8088 chip in 1979, followed by the Intel 80286, 80386, and 80486. In the late 1980s and early 1990s, the designations 286, 386, and 486 were well known to computer users as reflecting increasing levels of computing power and speed. Intel's Pentium chip is the latest in this series and reflects an even higher level.How Integrated CircuitComponents Are FormedIn an integrated circuit, electronic components such as resistors, capacitors, diodes, and transistors are formed directly onto the surface of a silicon crystal. The process of manufacturing an integrated circuit will make more sense if one first understands some of the basics of how these components are formed.Even before the first IC was developed, it was known that common electronic components could be made from silicon. The question was how to make them, and the connecting circuits, from the same piece of silicon? The solution was to alter, or dope, the chemical composition of tiny areas on the silicon crystal surface by adding other chemicals, called dopants. Some dopants bond with the silicon to produce regions where the dopant atoms have one electron they can give up. These are called N regions. Other dopants bond with the silicon to produce regions where the dopant atoms have room to take one electron. These are called P regions. When ...
关于wiht的问题1.
1. __A___ two exams to worry about , I have to work really hard this weekend. A、With B、Besides C、As for D、Because of 答:with是伴随情况用法。
2.It was a pity that the great writer died _B____ his works unfinished. A、for B、with C、from D、of 答:with也是伴随情况用法。
3. --- Would you like me to turn down the radio a bit? --- No , it's all right. I'm used to working _C____ the radio. A、as ; off B、for ; out C、with ;on D、during ; working 4.For miles around me, there was nothing but a desert, without a single tree _A__. A、in sight B、on earth C、at a distance D、in place 答:是表示距离用法。
5.The maths teacher walked into the classroom, _D____. A、with book in his hand B、a book in hand C、with a book in hand D、book in hand 答:是独立主格用法。
6.With nothing __A___ home, the boy was afraid to see his stepfather A、taken B、took C、taking D、to be taken 答:是过去分词做宾语补足语,容易与D混淆,D表示未然。
7.The girl reached a river bank __C___ so many flowers on both sides. A、growing B、with C、having D、of 答:此处选C是为了表达意思生动的用法。
8.With the boy __A___ him the way, the old man had no trouble finding his old friend's house. A、leading B、 led C、to lead D、was leading 答:此处选A是现在分词作宾语补足语的用法。
9. C_____ Mary _____ him, he is sure to pass the final exam. A、On ; helping B、For ; to help C、With ; to help D、with ; helping 答:本句是一般现在时态,故用动词不定式做宾补。
10. __B___ , they all left the hall in a great hurry. A、With the meeting was over B、The meeting being over C、The meeting was over D、When the meeting over 本题选择B,是独立主格用法。
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