Read the following text carefully and answer the question no-4, 5.

Stephen Hawking is considered the greatest physicist after Einstein. He was born in England in 1942. He was very skilled in mathematics from an early age. He wrote the book "A Brief History of Time: From the Big Bang to Block Holes" in 1988. In this book, he explained cosmology for the general public. It became famous and established his reputation as a great scientist. He received his PhD in cosmology from Cambridge University in 1968. But fortune did not favour him. In 1972, he became a victim of Gehrig's disease. Since then, he has been confined to a wheel chair with no power to control his body. But he continued teaching through the help of a computer. In 1974, he won the prestigious Albert Einstein Award for theoretical physics. In 1979, he joined Cambridge University as Lucasian Professor of Mathematics. He carried out his research work using his computer. Hawking had a motor neurone disease, and because of that he could not move or talk very well. The illness worsened over the years and he was almost completely paralysed. He used a wheelchair to move, and an Intel computer to talk for him. He died on 14 March 2018.