II. Past Simple or Present Perfect ? Read and complete the text with the correct form of the verbs in brackets.



Stephen Hawking is a world-famous scientist He (1)____ (not win),a Nobel Prize yet. He (2) ____(tell) us more about time than anyone jn the world. He (5) ______(always be) interested in time and questions like 'How (4)_______the world (start)?' and 'Can we go back in time?’ He (5) ______(write) his famous book: about time in 1988 and it (6)______ (already sell) more than eight million copies. Stephen Hawking (7) ________(be) wheelchair for most of his life because he has ALS. This means that information that tells his arms and legs to move does not go up his spinal cord to his brain. So his arms and legs don't move and breathing is a problem. In 1985 he (8)__________(go) to hospital because he couldn't breathe. Doctors (9)______(help) him to breathe but they had to take out his voice. He now speaks with the help of an American computer. ‘The computer (10) __ (give) me a voice but it's an American voice,’ Stephen often says, with a smile.