The Vikings, whose ancestors came from Scandinavia, were the first Europeans     1    (reach) America. They had lived in many places of northern Europe. In 982 AD, a man     2    (call) Eric the Red was forced to leave Iceland because of a murder, for     3    he got into trouble. Eric discovered Greenland and persuaded some people     4    (settle) in Greenland. Eric set sail again, but only half of the ships made     5    to Greenland this time.

Later a man, Biarni set sail from Iceland in search     6     Eris’s party. But he     7    (blow) off course and found himself in an unknown land, from where he     8    (eventual) reached Greenland.

In the year 1002, Leif, Eric the Red’s son, followed Biarni’s directions and sailed to     9    is believed to be the coast of present-day Canada. He also discovered Newfoundland. Actually, Eric the Red and Leif’s     10    (deed) are the first records we have of Europeans sailing to the Americas.

A great    1    (achieve) was made in 1953. Edmund Hillary and Tenzing Norgay climbed to the top of Mount Everest    2    (successful) at 11: 30 am, on May 29. They became the first people    3    (reach)the peak of Mount Everest.

Edmund Hillary was a New Zealand mountaineer, explorer and philanthropist, and Tenzing Norgay was a Nepali-Indian Sherpa mountaineer. Both of them were part of the    4    (nine) British expedition(探险)to Everest    5    (lead) by John Hunt in 1953. For this expedition, Hunt selected a group of people who were    6    (experience) in climbing mountains. In the group, Edmund Hillary    7    (select) from New Zealand, and Tenzing Norgay was actually from India where he lived. Before climbing, the expedition had been organized and planned for months. They made 9 camps on their way up, some of    8    have been still used by climbers up to now The first team made    9    to the place which was just 300 feet below the peak, and they left on May 26. They actually had already reached the point that no man had reached before. They were forced to leave because of the bad weather and besides, there were problems    10    their oxygen tank, too.

Cholera was a deadly disease of its day. Neither its cause nor its cure     1     (understand). So thousands of     2     (terrify) people died when there was an outbreak. John Snow wanted to solve     3     problem. He knew that cholera would not be controlled     4     its cause was found.

He became interested in two theories     5     possibly explained how cholera killed people. The first suggested that cholera     6     (multiply) in the air. The second suggested that people absorbed this disease     7     their bodies with their meals.

John Snow suspected that the second theory was correct but he needed evidence. So when another outbreak hit London in 1854, he was ready    8     (begin) his enquiry. With all the evidence he gathered, John Snow was able to announce with     9     (certain) that polluted water carried the virus.     10     (final) “King Cholera” was defeated.