It was playing computer games ____ cost the boy plenty of time ____ he ought to have spent doing his lessons.
268. The limited supply of water has been put into practice, take care to turn off the running ____ before you leave.
267. When he was very young, he made up his mind to be a doctor. Which of the following words can not be used instead of the underlined word?
266. Mr. Green's are at table now. The underlined part means ____.
265. Which of the following does not belong to the same category?
264. The invention of the coal-burning_______engine revolutionized industrial production in the 18th century and opened the way to the development of mechanized transport by rail and sea.