Câu hỏi:

Part 3: Questions 76 – 85. (2.0 points- 0.2/ each).

Read the text and think of the word which best fits each gap.

Food preservation

          Keeping food for long periods (76) _{…………………………} time was historically a huge problem. This proved especially crucial (77) _{…………………………} times when agricultural production (78) _{…………………………} severely limited by weather or crop failure. People commonly used ice to (79) _{…………………………} food fresh but, of course, ice itself melts relatively quickly. In 1859 an American, John Mason, (80) _{…………………………} a glass jar with a metal screw-on lid, creating a perfect seal and making (81) _{…………………………} possible to preserve food that would previously not have remained edible. Mason’s jar is still (82) _{…………………………} use throughout the world. An even (83) _{…………………………} successful method for keeping food by canning it in metal containers was perfected between 1870 (84) _{…………………………} 1920 by Englishman Bryan Donkin. This preserved food beautifully, though the early iron cans were expensive, heavy and difficult to open. A breakthrough came in the 1880s with the development of lighter materials (85) _{…………………………} also enabled mass production of cans.

Keeping food for long periods (76) _{…………………………} time was historically a huge problem.