________ is producted from the heat stored in the earth’s core 

According to a new report, today's generation of children are in danger of getting so (20) _______ sleep that they are putting their mental and physical health at risk.

What does the passage mainly discuss? 

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions. 

With his good sense of humour, Martin is quite ______ with the students

Mark the letter A, B, C or D on your answer sheet to indicate the word with the main stress different from that of the other three words in each question. 

A. ordinary    B. decompose    C. emphasis     D. calender

All of the following are mentioned in the passage as contributing to the ability to play modern violin music EXCEPT _________ 

If you want to get a good result in every work, you should have a constancy.

We're all ambitious - it seems to run in the family.