2. Analyze grammar in the underlined words and word combinations (in writing).

2. Make up 5 questions of different types to the text (in writing). Text 25

1. Read and translate the text in writing.

Electricity

Electricity is the phenomenon associated with stationary or moving electric charges. Electric charge is a fundamental property of matter and is borne by elementary particles. In electricity the particle involved is the electron, which carries a charge designated, by convention, as negative. Thus, the various manifestations of electricity are the result of the accumulation or motion of numbers of electrons.

Among the earliest electrical phenomena to be studied were those produced by stationary charges, or static electricity. The Greeks discovered that amber, rubbed with fur, attracted light objects such as feathers, and the word electric comes from the Greek electron, meaning amber. Serious study of electricity did not begin until the end of the 16th century, when William Gilbert investigated the relation of static electricity and magnetism. Benjamin Franklin proved the electrical nature of lightning in 1752 in his famous kite experiment, and he established the conventional use of negative and positive to distinguish kinds of charge. By the middle of the 18th century, two broad classes of electrical materials had been recognized: insulators, which acquired and retained a static positive or negative surface electric charge when rubbed, and conductors, mostly metals, which did not acquire a charge by rubbing but which were able to carry away the charge from an insulator. It was also found that a conducting body could store a charge if it was insulated from its surroundings. (The acquisition of surface charge by an insulator is now attributed to the ability of atoms either to lose an outer electron, and so exhibit a net positive charge, or to gain an outer electron for a net negative charge.) In 1767 Joseph Priestley established that electric charges attract with a force inversely proportional to distance, just as Newton had found gravity to do. The science of electrostatics was polished by Henry Cavendish, Charles-Augustin de Coulomb, and Simeon-Denis Poisson.

2. Analyze grammar in the underlined words and word combinations (in writing).

2. Make up 5 questions of different types to the text (in writing). Text 26

1. Read and translate the text in writing.

Types of viruses

Virus (computer), self-duplicating computer program that interferes with a computer's hardware or operating system (the basic software that runs the computer). Viruses are designed to duplicate or replicate themselves and to avoid detection. Like any other computer program, a virus must be executed for it to function—that is, it must be located in the computer's memory, and the computer must then follow the virus's instructions. These instructions are called the payload of the virus. The payload may disrupt or change data files, display an irrelevant or unwanted message, or cause the operating system to malfunction.

There are five categories of viruses: parasitic or file viruses, bootstrap sector, multi-partite, macro, and script viruses. Parasitic or file viruses infect executable files or programs in the computer. These files are often identified by the extension .exe in the name of the computer file. File viruses leave the contents of the host program unchanged but attach to the host in such a way that the virus code is run first. These viruses can be either direct-action or resident. A direct-action virus selects one or more programs to infect each time it is executed. A resident virus hides in the computer's memory and infects a particular program when that program is executed. Bootstrap-sector viruses reside on the first portion of the hard disk or floppy disk, known as the boot sector. These viruses replace either the programs that store information about the disk's contents or the programs that start the computer. Typically, these viruses spread by means of the physical exchange of floppy disks. Multi-partite viruses combine the abilities of the parasitic and the bootstrap-sector viruses, and so are able to infect either files or boot sectors. These types of viruses can spread if a computer user boots from an infected diskette or accesses infected files. Other viruses infect programs that contain powerful macro languages (programming languages that let the user create new features and utilities). These viruses, called macro viruses, are written in macro languages and automatically execute when the legitimate program is opened. Script viruses are written in script programming languages, such as VBScript (Visual Basic Script) and JavaScript. These script languages can be seen as a special kind of macro language and are even more powerful because most are closely related to the operating system environment.