What aspects of grammar do you need to work on?

Part B: Fill in each blank with the correct option.

The Story of the Internet 

Until the evening 13. of --- 4 October 1957, the US president, Dwight D. Eisenhower, was 14. confident --- that he led 15. the --- world's greatest nation. But the news that the Russians 16. had gone --- to space shook America's belief 17. in --- itself. The President turned to his Secretary of Defence. That single act 18. led --- to 19. the most --- important invention of the late twentieth century. On January 1958, ARPA  20. was formed --- that would control all of the government's high-technology work.

Bob Taylor, the man in charge of ARPA's computer projects in 1966, began his career as 21. a --- scientist  22. working --- on brain research. But he was also interested in computing, even before computer science 23. existed --- as a separate area of study. Larry Roberts, the manager of the project, thought packet switching sounded perfect for ARPAnet.

Packet switching is a very 24. efficient --- way to send data electronically. Each 25. message, ---   26. is broken --- down into pieces or 'packets'. The 27. packets --- are then sent out into 28. the --- communications network. Each packet 29. finds --- the best route to 30. its --- destination. When all the packets have arrived, they are put back together again 31. to form --- the original message. Packet switching also 32. takes --- advantage of the fact that data 33. used --- by nearly all computers is 'digital', which 34. makes --- it easy 35. to copy --- , break down and reassemble.

In 1972, a programme was invented which allowed a message 36. to be carried --- from one computer and 37. added --- to a mail-box of another machine. Each mail-box address had the sign @ 38. in --- it. Other networks began to appear but they could not talk to each other. It 39. was suggested --- that a kind of 'gate' 40. would be needed --- that would tell each network how 41. to communicate --- with others. The World Wide Web 42. was created --- 43. in --- 1989, which made the Internet easy to use, because of 44. the --- system of addresses - URLs - and 45. the --- new computer language, HTML. 

It is impossible to say what the Internet 46.will be --- like in the future, or how it will change people's lives. As more and more people 47. use --- the Internet, and as it 48. becomes --- cheaper and faster and 49. easier --- to use, there will be new things on the Internet that we cannot imagine today. But perhaps some of the more surprising events that 50. have happened --- recently can give us 51. a --- taste of the future.

Text source: Bryant, S. (2000). The Story of the Internet (Penguin Reader, level 5). London: Pearson. (Modified)Text