What is happiness to you

a. the plane may explode in the air.  b. the pilot may lose control of the plane.
c. the engines may be damaged.  d. too much air may get into the plane.
17. what might be the most suitable title for the text?
a. two important tests on planes  b. the importance of flying safely
c. the danger of testing planes  d. how planes are made and tested
e
the sahara festival is a celebration of the very recent past. the three-day event is not fixed to the same dates each year, but generally takes places in november or december. it is well attended by tourists, but even better attended by locals.
during the opening ceremonies, after the official greetings from the government leaders, people who attend the festival begin to march smartly before the viewing stands, and white camels transport their riders across the sands. horsemen from different nations display their beautiful clothes and their fine horsemanship. one following another, groups of musicians and dancers from all over the sahara take their turn to show off their wonderful traditional culture. groups of men in blue and yellow play horns and beat drums as they dance in different designs. on their knees in the sand, a group of women in long dark dresses dance with their hair: their long, dark shiny hair is thrown back and forth in the wind to the rhythm of their dance.
the local and visiting italian dogs are anxious to run after hares. the crowd is on its feet for the camel races. camels and riders run far into the distance, and then return to the finish line in front of the cheering people.
towards the evening, there comes the grand finale of the opening day, an extremely exciting horserace. all the riders run very fast on horseback. some riders hang off the side of their saddles. some even ride upside down--- their legs and feet straight up in the air---all at full speed. others rush down the course together, men arm in arm, on different horses. on and on they went. so fast and so wonderful.
18.the sahara festival is a festival which ________.
a .has a very long history in north africa
b. is held in the same place on the same day.
c. is attended mainly by the people in the sahara.
d. is celebrated mostly by travelers from different countries
19. before the races begin, ______ take part in the activities during the opening ceremonies.
a. musicians, dancers, horses and hares
b. camel riders, musicians, dogs and hares
c. horsemen, dancers, camels and dogs
d. musicians, officials, camels and horses
20. the underlined word “finale” in the fourth paragraph most probably means the _____ of the opening day.