... is D. was 2. What ` you ` about? You’re not hearing me, John! A. do – think B. are – thinking C. have – thought D. were – thinking 3. In my opinion, Carnival in northern Brazil ` the best ... It’s a lovely day today! The sun ` and the birds ` . A. is shining – are singing B. shines – sing C. is shining – sing D. shines – are singing 5. Since 1980, scientists in the world ` a lot of ... for a long time, but now I ` it up hopelessly. A. have tried – have given B. tried – have given C. have tried – give D. tried – will give 12. _________ there once a long time ago and __________...