: Read the passage and choose the best answer for each gap. (1,2m) Mars is called the Red Planet because of its reddish (21)…………….. There have been many explorations to Mars by humans since the mid-20th century. Scientists hope that we can find another planet to (22)…………………… human life.                There are major reasons why the  ( 23 )………..  on Mars is unsuitable for human life. Temperatures on Mars can be as low as -87 degrees Celsius and rarely get above 0 degrees Celsius. But the bigger problem is the lack of oxygen. 95% of the atmosphere is carbon dioxide (CO2), and this is (24)………….. to breathe. Moreover, there is no water on Mars even though scientists have found traces of it. Reason why we are be able to live on Mars.  (25)…………; as early as the mid-19th century, (26) ………… discovered that Mars had some similarities to Earth. A day on Mars is 24 hours, 39 minutes and 35 seconds, almost the same as a day on Earth. Mars also experiences seasons just as Earth does. However, the seasons are twice as long because a year on Mars lasts about twice as long as an Earth year. 21.         A. surface                             B. land                       C. ground                 D. body 22.         A. to accommodate                         B. accommodation   C. accommodate      D.accommodations 23.         A water                                   B. climate                   C. oxygen                   D. food 24.         A. poison                                  B. poisoning              C. to poison               D. poisonous 25 .         A. However                           B. Because                  C. Although               D . So 26. A. doctors                                      B. scientists              C. engineers           D. professors