Danh sách câu hỏi

Có 4,551 câu hỏi trên 114 trang

Read the passage and do the tasks that follow.

Li-Fi Technology

Li-Fi technology is a new technology that transmits signals as light instead of radio waves. In urban areas where Wi-Fi networks become congested and there is a lot of noise in the signals, this technology is something that can be of immense use to an individual. The basic requirement of this technology is the available of light!

Light is also an electromagnetic wave like radio waves. The only difference is that the former has the ability to transmit data almost ten thousand times faster than latter! The basic process is quite simple to understand. An LED light bulb, any one at all, can be flicked on and off in order to be able to generate signals. A light sensor on a device picks up the digital information sent by the LED, which enables it to be processed by a computer.

The question is whether anyone wants to go through the annoying experience of sitting under a flickering light bulb. This is the interesting part. The technology is focusing on make sure that the light bulb is flickered up to billions of times a second! At that rate, the human eye simply cannot notice the light bulb being flicked on and off.

However, everything comes with a disadvantage. The major disadvantage here is the fact that these signals cannot penetrate walls. So if you want to move from one room to another, you will need to have a wired bulb present in that room as well.

An Estonian startup company called Velmenni took the technology out of the laboratories and brought it into the real-world offices, and industrial environments in Tallinn for the first time.

Overall, this sounds like quite a development in the field of communication technology.

Read the passage, and then decide whether the statements are true (T) or false (F)

1. Li-Fi is similar to the Wi- Fi except that it uses light waves instead of radio waves.

2. The speed generated by Li-Fi can be up to ten thousand times greater than the average Wi-Fi

3. No one wants to go through the annoying experience of sitting under a flicking light bulb.

4. It is convenient for you to use Li-Fi to transmit signals when you move to various rooms in the building.

5. The technology of Li-Fi has several of advantages in theory, but we cannot put into practice.

Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage.

The Fitbit Flex is a mobile device aimed at planning your exercise, diet, and sleep. It’s very easy to wear it all the time. It is very light and comfortable, and it looks casual and natural on your wrist. When I need to wear a watch, I have one that sits (26)...............the Flex quite easily. You can get different Fitbit Flex

wristbands. Reasaonably priced, with dozens of fun colors!

I was pleasantly surprised to learn how many steps I walk during my normal working day. I actually find ways to fit in even more activities (27)..................., so I can watch the numbers go up. It’s water – resistant, so I can wear it in the shower or in the rain without worrying about keeping it dry. The Fitbit synchronizes with my smartphone via Bluetooth.

Tracking food items (28)....................it possible for the Dashboard to display a calorie budget for you, comparing calories consumed versus calories burned. It will use the daily calorie total you create to show you how many calories left in the day.

While I’m sleeping, the Fitbit Flex measures the movements of my wrist, logging my sleep (29)...............awake, restless, or asleep. It has been fascinating to see my sleep pattern each night and over time.

There is a notification alert to let me know when my battery is running low. After 10 minutes or so in the

charging cable, it’s good to go again. The Fitbit Flex battery needs (30)...................every 3 to 5 days.

When I need to wear a watch, I have one that sits (26)...............the Flex quite easily. You can get different Fitbit Flex wristbands.