Work in pairs and complete the information. Use the words below in the correct form. You need to use some words more than once.

 lose      conductor      superconductor   discover    conductive      

  resistance      mercury               cool             below          superconductive

When an electric current is passed through a conductor some of the energy   ______ in the form of heat and light. The amount of energy lost varies depending on the individual material’s electrical _________. Some materials, like copper and gold, are great _______ of electricity and have very low ________. Scientists __________ that the colder these materials are the more ________ they become. But no matter how cold you make copper or gold, it will always show some electrical ___________. Mercury, however, is different. In 1911, when scientists _______ a sample of ________to 4.2 degrees above absolute zero, its _______ abruptly disappeared: the first _________ was discovered. Gradually, more and more superconductive materials have been found that show zero electrical resistance _______a certain critical temperature. When _________ is zero, electricity is conducted perfectly, without any loss and a current can theoretically flow in a closed loop for ever. This has been demonstrated by scientists who have sustained electrical currents in superconductive rings for years without any measurable depreciation of energy and it doesn’t end there; not only do ______________ have absolutely zero________ they also don’t like to let magnetic fields to pass through.

10 Watch the first part of the video “ Superconductors ” (1:08) and check your answers.

11 Watch the second part of the video. “Superconductors” Then complete the dialogues and present them to the class.

Student A: -What materials are known as high-temperature superconductors?

Student B - I suppose materials that ____________________________________________

               - But still, always having to have liquid nitrogen at hand is _________________

                - Well, it is the goal for scientists to create a material that is________________

                  If we had _______________________________________

                  we’d be able to power devices using much less power; none of the

                  energy would be lost as heat, changing the way that electronic devices are

                  designed and built.

 

Student A: - Have you seen the Meissner effect in action with science experiments?

Student B: - Yes, I’ve seen the video.

 - Could you describe it?

 - I’ll try. A __________is put on top of a _______________________ and

___________ temperature nothing really special happens, but when the material

is _____________ to its critical temperature the Meissner effect kicks in, causing

the_______________ as if by magic..    

    

Student A: -We can’t forget that superconductors have to be kept at ___________________

                   ________________ in order to function properly.   

Student B: - And this is the main factor limiting the _________________________________

                 - Fortunately, scientists have been busy finding and creating materials that ______

                   _________________ at higher and higher temperatures.

 

 

Study the rules.

I WISH I HAD KNOWN

 

To express hypothetical or unreal wishes about the situations that existed in the past, we use If + had (‘d) … (if I had known / been / done etc.)

 If I’d seen you, of course I would have said ‘hello’ (The real situation was that I didn’t see you)

We use had + done / known / been in the same way after wish. I wish something had happened = I am sorry that it didn’t happen.

  I wish it had been warmer while we were away. (The real situation was that the weather was cold).

 

13. Imagine that you are talking about the past. For each situation, write a sentence with I wish…

    Example: You studied French at your university. Now you need English for your work.

                I wish I had studied English instead of French when I went to university.

              

1. When you were a freshman you missed a lot of classes. Now you think that it was silly.

I wish…

2. There was a job advertised in the newspaper. You decided not to apply for it. Now you think

that your decision was wrong.

I wish…

 3. When you were younger you didn’t learn to play a musical instrument. Now you regret this.

I wish …

4. You didn’t study science, you studied languages. Now you want to become an engineer.

I wish …

5. There was an international conference at your university last month. You didn’t take part in it.

Now you regret this.

I wish…

6. You didn’t do your homework and the teacher told you off.

I wish…

 

Study the rules

 

 I WISH… WOULD

 

We use I wish … would … when we want something to happen or when we want somebody to do something. The speaker is not happy with the present situation.

I wish you would listen to me.

You can use I wish …wouldn’t to complain about things people do repeatedly:

I wish you wouldn’t keep interrupting me.

We use I wish … would for actions and changes, not situations. Compare:

I wish John would come. (= I want him to come)

but I wish John were (or was) here now. (not ‘I wish John would be’...)