Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
We were quite impressed by the ______ students who came up with the answer to our question almost instantly.
A.absent-minded
B.big-headed    
C.quick-witted  
D.bad-tempered

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Read the following passage and mark the letter A, B,C, or D on your answer sheet to indicate the correct answer to each of the questions from 51 to 60. 
The ability to conduct electricity is one of the key properties of a metal. Other solid materials such as silicon can conduct electricity but only effectively at certain temperatures. Also, some substances such as salt (sodium chloride) can conduct when molten or when dissolved in water. The ability of metals to conduct electricity is due to how their atoms bond together. In order to bond together the metal atoms lose at least one of their outermost electrons. This leaves the metal atoms with a positive charge and they are now strictly ions. The lost electrons are free to move in what is known as a sea of electrons. Since the electrons are negatively charged they attract the ions and this is what keeps the structure together.
An electric current is a flow of charge and since the electrons in the sea of electrons are free to move they can be made to flow in one direction when a source of electrical energy such as a battery is connected to the metal. Hence we have an electric current flowing through the wire, and this is what makes metals such good conductors of electricity. The only other common solid conducting material that pencil users are likely to encounter is graphite (what the ‘lead’ of a pencil is made from). Graphite is a form of carbon and again the carbon atoms bond in such a way that there is a sea of electrons that can be made to flow as an electric current. Likewise, if we have an ionic substance like salt we can make the electrically charged ions flow to create a current but only when those ions are free to move, either when the substance is a liquid or dissolved in water. In its solid state an ionic substance like salt cannot conduct electricity as its charged ions cannot flow.
Electrical insulators are substances that cannot conduct electricity well either, because they contain no charged particles or any charged particles they might contain do not flow easily. Water itself is a poor conductor of electricity as it does not contain a significant amount of fully charged particles (the ends of a water molecule are partly charged but overall the molecule is neutral). However, most water we encounter does contain dissolved charged particles, so it will be more conductive than pure water. Many of the problems that occur when touching electrical devices with wet hands result from the ever-present salt that is left on our skin through perspiration and it dissolves in the water to make it more conductive
The word “outermost” in paragraph 1 mostly means ______. 
A.furthest from the inside                   
B.nearest to the inside
C.the heaviest                                       
D.the lightest

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 10 to 14.
In the past, technology and progress was very slow. People “invented” farming 12,000 years ago but it took 8,000 years for the idea to go around the world. Then, about 3,500 years ago, people called “potters” used round wheels to turn and make plates. But it took hundreds of years before some clever person thought, if we join two wheels together and make them bigger, we can use them to move things
In the last few centuries, things have begun to move faster. Take a 20th-century invention like the aeroplane, for example. The first aeroplane flight on 17 December 1903 only lasted 12 seconds, and the plane only went 37 metres. It can't have been very exciting to watch, but that flight changed the world. Sixteen years later, the first plane flew across the Atlantic, and only fifty years after that, men walked on the moon. Technology is now changing our world faster and faster. So what will the future bring?
One of the first changes will be the materials we use. Scientists have just invented an amazing new material called grapheme, and soon we will use it to do lots of things. With grapheme batteries in your mobile, it will take a few seconds to charge your phone or download a thousand gigabytes of information! Today, we make most products in factories, but in the future, scientists will invent living materials. Then we won't make things like cars and furniture in factories - we will grow them!
Thirty years ago, people couldn't have imagined social media like Twitter and Facebook. Now we can't live without them. But this is only the start. Right now, scientists are putting microchips in some disabled people's brains, to help them see, hear and communicate better. In the future, we may all use these technologies. We won't need smartphones to use social media or search the internet because the internet will be in our heads!
More people will go into space in the future, too. Space tourism has already begun, and a hundred years from now, there may be many hotels in space. One day, we may get most of our energy from space too. In 1941, the writer Isaac Asimov wrote about a solar power station in space. People laughed at his idea then, but we should have listened to him. Today, many people are trying to develop a space solar power station. After all, the sun always shines above the clouds!
What does the writer say about the future of communication?
A.We can't know what the most popular social media will be.
B.Microchips will become faster.
C.We won't use the internet as much.
D.We won't need devices like smartphones.