Unit 3. What’s Your Knowledge? » Стр.66 (13c-d)

Complete the text with the right form of the past simple passive (positive or negative) of the verbs below. Many centuries ago food (1) was stored in icehouses, which (2) were placed near freshwater lakes or packed with snow and ice during the winter. Mechanical coolers (3) were designed until the mid 19th century, but the first domestic electric refrigerators (4) were invented in 1923 by B. Von Platen and C. Munters from Sweden. d) Spot the mistake in the following text and correct it. The first heart transplant was successfully performed in 1967 by Dr Christian Barnard in Cape Town, South Africa. Many types of such surgerles are now done worldwide and have saved many lives.