Unit3 Tomorrow’s World單元學案

20、a fast food restaurant is the place ________ ,just as the same suggests, eating is performed quickly.     a which           b where              c there                d what b.短文填空  the year is 2094. it has been announced that a comet（彗星） is heading towards the earth. most of it will miss our planet, but two pieces will probably    the southern half of the earth. ______17 july, a piece four kilometers wide enters the earth’s        （大氣層） with a massive explosion. about half of the piece is destroyed, but the       part hits the south atlantic at 200 times the      of sound. the sea boils and a huge hole is made in the sea bed. huge waves are created and spread        from the hole. the wall of water, a kilometer high, rushes towards southern africa at 800 kilometers an hour. cities on the african       are totally destroyed and millions of people are_______   .before the waves reach south america, the second piece of the comet      in argentina. earthquakes and volcanoes are      off in the andes mountains. the shock       move north into california and all around the pacific ocean. the cities of los angeles, san francisco and tokyo are completely      by earthquakes. millions of people in the southern half of the earth are already dead,       the north won’t         for long. because of the explosions, the sun is hidden by clouds of dust, temperatures around the world      to almost zero. crops are ruined. the sun won’t be seen again for many years. wars break out as countries fight for    a year later, no more than 10 million people remain         .could it really happen? in fact, it has already happened more than once in the history of the earth. the dinosaurs（恐龍） were on the earth for over 160 million years. then 65 million years ago they suddenly disappeared. many scientists believe that the earth was hit by a piece of object in      . the dinosaurs couldn’t live