Reading. 4.Read the text, find the sentences in the Present Indefinite Tense and explain its usage

4. Read the text, find the sentences in the Present Indefinite Tense and explain its usage.

Transistors are devices that control the movement of electrons, and consequently, electricity. They work something like a water faucet – they do not only start and stop the flow of a current, but they also control the amount of the current. With electricity, transistors can both switch or amplify electronic signals, letting you control current moving through a circuit board with precision.

In a computer chip, the transistors aren't isolated, individual components. They're part of what's called an integrated circuit (also known as a microchip), in which many transistors work in concert to help the computer complete calculations. An integrated circuit is one piece of semiconductor material loaded with transistors and other electronic components.

Computers use those currents in tandem with Boolean algebra to make simple decisions. With many transistors, a computer can make many simple decisions very quickly, and thus perform complex calculations very quickly, too.

Computers need millions or even billions of transistors to complete tasks. Thanks to the reliability and incredibly small size of individual transistors, which are much smaller than the diameter of a single human hair, engineers can pack an unfathomable number of transistors into a wide array of computer and computer-related products.

5. Complete this description of how transistors in logic gates work, using the correct form of the verbs in the box.

be work give help make need have compare

In practice, you (1) …… not ……… to know any of this stuff about electrons and holes unless you're going to design computer chips for a living! All you need to know is that a transistor (2) …………. like an amplifier or a switch, using a small current to switch on a larger one. But there's one other thing to know: how (3) ……..all this………computers store information and make decisions?

We can put a few transistor switches together to make something called a logic gate, which (4) …………….several input currents and (5) …………a different output as a result. Logic gates let computers make very simple decisions using a mathematical technique called Boolean algebra. Your brain (6) ………… decisions the same way. For example, using "inputs" (things you know) about the weather and what you have in your hallway, you can make a decision like this: "If it's raining AND I (7) …………an umbrella, I will go to the shops". That's an example of Boolean algebra using what's called an AND operator. You can make similar decisions with other operators. "If it's windy OR it's snowing, then I will put on a coat" is an example of using an OR operator. Or how about "If it's raining AND I have an umbrella OR I have a coat then it's okay to go out". Using AND, OR, and other operators called NOR, NOT, and NAND, computers can add up or compare binary numbers. That idea (8) ……………the foundation stone of computer programs: the logical series of instructions that make computers do things.

6. Make your own positive, negative and interrogative sentences about transistors in the Present Indefinite Tense.

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